Philosophy and Philosophers - an Introduction to Western Philosophy - Chapter 5

back to ...

https://sites.google.com/site/philosophygreekancient/philosophy-and-philosophers---an-introduction-to-western-philosophy---chapter-1-3

or ...

CHAPTER FIVE

Empiricism: Locke, Berkeley, Hume

The empiricists in general have tendencies which contrast with those

of the rationalists. Empiricists hold that all the material for knowledge,

our ideas or concepts, and all knowledge of actual matters of fact, as

opposed to logical or conceptual truths, must be derived from, or be

reducible to, aspects of our experience: features of the information

provided by the content of our senses and introspection. Empiricists

deny that it is possible to know by reason alone the nature of what

exists; rather, the nature of what exists can be known only through

experience. We should reject as meaningless ideas or concepts which

cannot be specified as corresponding to any possible experiences. We

should reject knowledge claims concerning matters of fact about the

nature of the world which are not supportable by the evidence of

experience. This leads to a tendency among empiricists to emphasize

that the limit of human knowledge and imagination is bounded by the

limit of our experience. Empiricists reject the rationalist claim that it is

possible to come to know by a priori reason alone the nature of an

intelligible real world inaccessible to experience that stands beyond

appearances. The empiricist may argue that concepts (such as

substance), and the terms that express them, are meaningless or else

must relate to some possible experience, since concepts and terms get

their meaning by reference to some possible experience, but a world

beyond experience cannot be a world that might possibly be

experienced; in either case it is not possible to use meaningful concepts

to talk of a world beyond possible experiences.

The tendency in empiricism is also to deny the existence of natural

necessity: necessity is a property only of logical relations between

concepts, or of logical relations between ideas or thoughts, not

between things or events in the world whose existence, nature and

connections are all contingent; such natural contingent connections can

be discovered not by reason, which can establish only necessary truths

and necessary connections, but only by experience.

114

Empiricism is inclined to argue that there are two exclusive and

together exhaustive types of proposition.

(a) Propositions whose truth, logically speaking, can be known

merely by understanding them, or by deductive reasoning alone,

independently of the evidence of experience: truths of reason.

(b) Propositions whose truth, logically speaking, cannot be known

merely by understanding them, or by deductive reasoning alone,

but which depend on the evidence of experience: truths of fact.

All propositions which tell us anything about the real or actual world

are truths of fact. Propositions stating matters of fact cannot be known

to be true merely by our understanding them, or by our deducing them

from other propositions known to be true by the understanding alone;

if we can know them to be true at all, they must be known through

consulting experience. It should be noted that the distinction is not the

genetic one of how we come to have, acquire, or understand these

different sorts of proposition, but a logical question concerning on

what, once acquired or understood, the truth or falsity of a proposition

depends, and on what knowledge of the truth or falsity of a

proposition depends. If the truth or falsity of a proposition depends

only on the meaning of the terms in it, then it is an a priori proposition

whose truth or falsity can be known a priori by reason alone

independently of empirical evidence. If the truth or falsity of a

proposition does not depend only on the meaning of the terms in it,

then it is an a posteriori proposition whose truth or falsity can only be

known a posteriori by empirical evidence, not by reason alone.

The basic contrast between rationalism and empiricism is an

argument about the extent and nature of what truths it is logically

possible to know a priori by the understanding independently of

experience, by intellectual intuition and pure logical reasoning alone,

and what truths it is logically possible to know a posteriori by the

senses, by experience and observation alone. The rationalist argues

that certain things can be known with certainty to be necessarily true

about the nature of reality, what exists, by a priori reason alone, even

if such truths refer to a reality that lies behind appearances. This the

empiricist denies, arguing that claims to knowledge of truths

concerning the nature of reality or the actual world must seek their

justification, if such justification is possible at all, in experience; a

priori reason alone cannot reveal the real or actual nature or existence

of the world. Reason alone can give knowledge only of what is

necessary (that which must be because its denial is contradictory),

impossible (that which cannot be because its assertion is

contradictory), and possible (that which may or may not be because

its denial is not contradictory), but not what is actual among what is

merely possible or contingent (not impossible and not necessary). If

the premises of a valid deductive argument are true, then the

Locke, Berkeley, Hume 115

conclusion must be true. A deductively valid argument is one in

which to assert the premises and deny the conclusion would be a

contradiction. Conclusions can be validly deduced from premises

independently of the evidence of experience; but if the conclusions

are factual, then such deductions must involve factual premises

which can be known to be true not by reason alone but only by the

evidence of experience; without the evidence of experience any

factual conclusion of a deduction is at best hypothetical and not yet

known to be true.

The spectre raised by empiricism is of two exclusive and together

exhaustive sets of truths: one set is necessary, certain and known a

priori, but says nothing about the actual nature of the world; the other

set is contingent, not certain and known, if at all, a posteriori, but can

say something about the actual nature of the world; this undermines

the search for necessary and certain knowledge about the actual nature

of the world by leaving all truths about the actual nature of the world

both contingent and not certain.

Locke

John Locke (1632–1704) was born in Wrington in Somerset and died

at Oates in Essex. Locke was far from being the caricature of the

philosophical recluse; he was, on the contrary, a man well known in

public affairs, sometimes involving considerable danger; but, despite

his close involvement with controversial political affairs, Locke was

a prudent man. Locke’s father was a lawyer and a staunch Puritan

and Parliamentarian who fought with the Parliamentarian army in

the English Civil War; this began in 1642 against Charles I, who was

beheaded in 1649. Locke attended Westminster School, and in 1652

he went to Christ Church, Oxford. At Oxford he studied the arts

course of logic, grammar, rhetoric, Greek and moral philosophy.

After obtaining his BA he was elected in 1658 to a Senior Studentship

at Christ Church which was tenable for life. He taught Greek and

moral philosophy, but soon became interested in medicine, and

attained the BM (Bachelor of Medicine) degree from the University

of Oxford in 1674.

It was during his time at Oxford that Locke became dissatisfied with

the philosophy of scholasticism and first became acquainted with, and

derived inspiration from, the works of Descartes. Locke was elected a

Fellow of the Royal Society in 1668; there he came to know the chemist

and physicist Robert Boyle (1627–92), whose emphasis on

experimental method and the corpuscular theory of the constitution of

matter impressed and decisively affected Locke: it influenced his

philosophical thought, particularly in its rejection of Aristotelian

modes of physical explanation. Sympathetic to Locke’s views is the

116 Empiricism

motto of the Royal Society, Nullius in verba: “Nothing by mere

authority”. Locke’s thought, both in its purely philosophical as well as

in its political interests, is consistently marked by the advocation of

tolerance and resistance to dogmatism in the face of the limits and

uncertainties of human knowledge. His political thought, as embodied

in the Two treatises on government (1690), became a philosophical

foundation of liberal democracy.

After Cromwell’s Commonwealth, the monarchy was restored in

1660 under Charles II. Through his interest in medicine, Locke had

initially become in 1667 a medical adviser to Lord Ashley, later the Earl

of Shaftesbury. Locke in fact left his college, never to teach there again,

and instead entered into a series of official appointments. Between

1675 and 1679, Locke spent time in France mainly for the sake of his

poor health. His travels in Europe fostered his keen interest in all

aspects of contemporary scientific work. This association and

friendship with Shaftesbury was to bring Locke problems; Shaftesbury

was party to the failed attempt to overthrow and replace Charles II

with Charles’s illegitimate offspring, the Protestant Duke of

Monmouth. Shaftesbury, fearing impeachment for treason, fled to

Holland in 1682, and died the next year; Locke also wisely, because of

his support of Shaftesbury and Monmouth, moved to, and for a time

hid in, Holland under a false name, until returning to England after

the Glorious Revolution of 1688, when the Catholic Stuart King, James

II, fled the English throne, to be replaced by the Protestant William of

Orange, which led to the Hanoverian Succession. From 1691 Locke

lived at Oates in Essex in the house of Sir Francis and Lady Masham

until his death in 1704.

It is important to understand the overall aim of Locke’s philosophy:

it is concerned mainly with determining the nature, scope, and limits

of knowledge and with giving an account of the nature of reality.

Locke’s position stands in contrast to that of many of his philosophical

predecessors and, indeed, some of his philosophical successors. The

heart of the matter lies in the interplay between scepticism and the

scope of human knowledge; and it can be summed up by the aim of

discovering what it is human beings are and are not fitted to know.

Locke accepts that knowledge, properly speaking, is of truths which

are certain and universal. Our inability to refute scepticism in various

areas of human inquiry where we wish to claim to know truths might

lead us to the despairing view that only scepticism can remain in those

areas. Locke emphasizes the limits of human knowledge proper, but in

a way that allows for areas where, although we do not have

knowledge in the strict sense, we are not thereby forced into scepticism

because in many of these areas of inquiry we are still capable of

probable belief; and, indeed, the belief is sometimes so probable that it

is virtually as good as knowledge. What Locke is advocating might be

called degrees of appropriate certainty. This presents us with

Locke 117

something other than a choice between strict knowledge and total

ignorance. In those areas where we cannot strictly speaking know,

Locke argues that we should acknowledge that we have reached our

limitations; but knowledge in the strict sense is usually not required;

the probable belief we may have instead is sufficient for our purposes,

and this, although not a refutation, is the answer to the sceptic. Locke

advocates the view that absolute certainty in many important areas of

human inquiry is not possible for us but nor is it required or even

appropriate; an example is our degree of certainty about the existence

of an external world.

Locke’s strategy in delimiting human knowledge is to examine the

power of the human mind and the objects of thought: ideas. The

philosophy of Locke stands on two main foundations: first, that all

knowledge derives from reasoning about our ideas and, secondly, that

all ideas originate in experience. We cannot in our thinking and

knowledge go beyond the ideas or concepts we actually have—ideas

are the materials of thought and knowledge—and the ideas we have

are bounded by what ideas can be attained through experience.

From this it is not surprising to find that Locke opposes what he

regards as a prevalent notion that we have innate, or inborn, ideas in

the mind independently of experience. It soon becomes clear that what

Locke is most concerned to oppose is the existence in the mind of

innate principles and knowledge; although in denying the existence of

innate ideas—ideas being the building blocks of knowledge—Locke is

also denying innate knowledge of truths. One of the chief motives for

Locke’s denial of innate knowledge is that the identification of a

principle as innate or inborn is sometimes used, especially in moral

matters, as a block to any questioning of the truth of that principle. But

we must, Locke says, think through what we claim to know, and make

knowledge our own. This goes along with Locke’s general suspicion of

authority as a valid ground for accepting something as true.

Apart from certain moral principles alleged to be innate, there were

also said by advocates of innate ideas to be innate basic logical

principles, such as “Whatever is is”. One of the arguments used in

favour of innate principles is that there are some principles that are

universally assented to as true, and this shows them to be innate rather

than acquired. Locke flatly denies that there is such universal assent;

children and idiots just do not assent to abstract principles; but he goes

on to say that even if universal assent were a fact, this would not show

that the universal assent could not be explained in some other way

than by saying that what is assented to is innate. In fact Locke thinks

the argument from immediate universal assent to the conclusion that

particular principles are innate confuses innateness and cases of selfevidence;

the universal assent, on encountering a self-evident

proposition, is fully accounted for by the relation of the terms in the

proposition, meaning we cannot think otherwise if we understand it at

118 Empiricism

all. Locke rejects the idea that there might be innate principles

implicitly in the mind which are not explicitly understood. Moral

rules, which are supposedly innate, are not even self-evident and they

therefore demand reasons to be given for their acceptance. Moreover,

the abstracted ideas or concept terms of abstract principles suggested

as innate can be acquired only after experience of the particular cases

and the gaining of particular ideas.

Locke does not deny the existence of innate capacities—the power to

perceive, believe, recognize truth and falsity, judge, assent to

principles—but none of these capacities actually amounts in itself to

possessing innate ideas, principles or knowledge of truths. If

innateness merely amounted to the capacity to recognize and assent to

truths when presented, then all knowledge, since it involves this,

would be innate—which Locke thinks is absurd.

Locke never questions whether even if there were innate principles

this would make any difference to whether those principles were true;

he never questions the truth of putative innate principles. The reason

for this is Locke’s piety; if there were innate principles they would

have to be true because they could be implanted directly in us only by

God. Locke argues that there are, in fact, no innate ideas and

principles, so the question of their truth or falsity does not arise, and

the positing of them is unnecessary to explain the knowledge we have.

The explanation for all the ideas we have is that they originate in

experience: experience is made up of sensation derived from external

material objects, and reflection derived from awareness of the workings

of our own mind. Examples of ideas of sense-experience are yellow,

elephant, cold, army; examples of ideas of reflective-experience are

thinking, believing, willing, doubting.

Locke is not free from the charge of confusing psychological or

genetic empiricism with philosophical or logical empiricism. Genetic

empiricism is a psychological theory accounting for the way we

actually come to have, or acquire, ideas and knowledge of which

propositions are true and which false; philosophical empiricism is

concerned only with that on which the truth or falsity of propositions

depends and what is logically required in order to justify the claim to

know whether the propositions are true or false. This makes the

distinction between knowledge of truths being psychologically innate

and its being logically a priori. Showing that a certain proposition is,

psychologically speaking, entertained in the mind at a time prior to

any experience would not show whether that proposition were true or

false or have any relevance to justifying logically a claim to know it to

be true or false. Whether a proposition can be known to be true or false

logically independently of experience is not shown by discovering

whether it was in the mind innately or not, but by deciding of what

logical type the proposition is.

Take the following two propositions:

Locke 119

(a) The internal angles of a plane triangle add up to 180 degrees.

(b) There are lions in Africa.

If the truth of (a), which is a necessary truth, were questioned, we

would prove it to be true by showing it is deducible from the axioms of

Euclidean geometry; if (b), which is a contingent truth, were

questioned we could only establish its truth by going to Africa and

looking. The truth of (a), and knowledge of that truth, is, logically

speaking, independent of evidence of experience, whereas the truth of

(b), and knowledge of that truth, is, logically speaking, knowable only

through the evidence of experience. Whether a truth is knowable a

priori or a posteriori is determined by whether the truth can possibly be

established empirically or non-empirically; and this is different from

the truth being actually innate or acquired. We might possess no nonempirical

truths such as (a) innately; but that would not alter the fact

that these propositions are true regardless of any states of affairs in the

world, and they can be known to be true independently of experience

and by pure logical reasoning. We might possess a whole stack of what

turn out to be empirical truths such as (b) innately, and although this

might be psychologically surprising it would not alter the fact that the

truth of these propositions depends on certain states of affairs in the

world obtaining, and they can be known to obtain only through

experience, not by pure logical reasoning alone. A truth such as “Either

it is raining or it is not raining” (“p or not-p”) is an a priori truth

because it is true independently of any states of affairs in the world,

and it logically can be known to be true independently of inspecting

the weather; but it tells us nothing about the weather; it does not help

us to decide if we should take an umbrella. All propositional beliefs,

even if true, which are not logically a priori can be known to be true

only by checking them against the evidence of experience, regardless

of whether we have the beliefs innately or not. Those truths known

independently of experience are said to be necessary in that their

denial implies a contradiction; those truths known only by experience

are said to be contingent, as their denial does not imply a

contradiction. The philosophical concern should be to distinguish

between a priori propositions, which are all those propositions where

the logical justification of knowledge of whether they are true or false

is independent of empirical evidence, and a posteriori propositions,

which are all those propositions where the logical justification of

knowledge of whether they are true or false is dependent on empirical

evidence.

There is considerable uncertainty and controversy over what Locke

means by “idea”. Locke defines an idea as “whatsoever is the object of

the understanding when a man thinks”. Some have taken Locke to

mean by “idea” some kind of mental entity—mental images which are

objects in the mind. The consequence of this (a point raised by

120 Empiricism

Berkeley) is that it immediately leads to scepticism about knowledge

through perception of the external world. If the “veil of perception” or

“picture-original” view is correct, and we only ever perceive ideas in

the mind, then there can be no way of checking if the ideas represent

the external world truthfully, or even if there is an external world at all

corresponding to the ideas. We are locked in a circle of ideas, with the

knower logically blocked off from what is known; our ideas are a

barrier between us and what the ideas are ideas of. Partly because of

this point, which seems too obvious for Locke to have missed, and

which he even seems to point out, other interpreters of his work

suggest an alternative view in which the reification of ideas is resisted.

Locke, it is said, means by “idea” in “idea of X” a mental or perceptual

act, not a thing; “idea” refers to our understanding of X, or our

perception of X, as distinct from X itself; “idea of X” means “X-as-it-isperceived/understood/known/appears”;

and it expresses the

epistemological relation between the knower and the thing known. To

avoid a regress, what must ultimately be caused in the perceptual

process is an act of perceptual awareness itself, not another object of

which to be aware. An “idea of X” involves two entities, knower and

object known, not three by including an entity “idea of X”. The

expression “idea of” points out that our conception or perception of an

object is our conception or perception; it is how it appears to us, as

opposed to how the object is in itself, which may differ from our idea.

This emphasizes the assertion that we inevitably view things under the

constraint or qualification of their being seen from our point of view—

how things appear to us—and that we cannot attain the God’s-eye

view of knowing objects as they are in themselves quite independently

of all reference to its being our perspective. To say I have an idea of X

is just to say I have some understanding of the object X. On this

interpretation, when Locke speaks in a variety of ways about a relation

of resemblance or non-resemblance between ideas and what they are

ideas of, he is not committing himself to this being like the relation

between a picture or image and an original—literal picturing—but

rather the kind of relation that holds between an accurate and

inaccurate description and the object described.

Locke divides ideas into simple and complex. Complex ideas are

compounds of simple ideas. We may experience ideas in complexes, or

even only in complexes, but they must be reducible to simple atomic

unanalyzable ideas. The thinking behind this is that at some point

there are ideas which cannot be broken down into anything simpler

and to have the ideas at all one must derive them directly from

experience. If one has never experienced the simple idea of red, there is

no way that having the idea can be explained by showing how it is

compounded of simpler ideas one has experienced; whereas the idea

of a mermaid, even if one has not encountered mermaids in one’s

experience, is made up of ideas one has encountered in experience.

Locke 121

Locke is not saying that we always experience simple ideas first, and

then build up compounds, merely that all compounds must be

analyzable into simple ideas of which we have had direct experience.

Locke’s position places restrictions on the scope of imagination:

whatever we make up we will only ever be compounding simple ideas

that ultimately originate in experience.

For Locke the meaning of a word derives from its standing for, and

its association with, an idea or complex of ideas; we know the meaning

of a word when we know the idea it stands for. If someone has not

experienced the simple idea X, then he will not understand the

meaning of the word standing for X. We will, in attempting to speak

about that which is, strictly speaking, beyond our experience and is in

no way analogous to anything in our experience, be using meaningless

expressions and talking nonsense because we will be unable to specify

any idea for which the word stands.

If it is the case that we only ever encounter particulars in our

experience from whence we derive particular ideas, the problem arises

as to how we come by abstract general ideas, for which general words

stand as signs—such as “redness”, “man”, “nurse”—which can apply

equally to many particulars. Such general terms are necessary for

communication and knowledge. Pure nominalism holds that all that

any group of particulars under a general name have literally in

common is the sharing of that name; but this leaves unanswered the

problem of universals: namely how we know which particulars come

under that general name in the first place. Locke has more than one

answer. His first answer is that we are blessed with a faculty of

abstraction: by a process of omission the abstract general idea is

formed by leaving out of each idea of particular members of a similar

class all those characteristics in which they differ, thereby including

only that which is common. The general idea will itself be a particular;

but it is not clear what the resultant idea amounts to. Berkeley argues

that Locke’s procedure is impossible: if we take away all particular

features we are left with an impossible idea; we could not represent to

ourselves a red which is no particular shade of red at all; there cannot

be an idea which is merely determinable. Locke’s second answer is that

the meaning of abstract general ideas and words is fixed by “nominal

essences”: we notice similar characteristics between particulars, and

we decide on some set of defining objective particular characteristics

by which we then have the ability to recognize whether any particular

is correctly admitted to a specific general class.

Locke explains the relation between our ideas in the mind of

sensible qualities of external objects and those sensible qualities as

they exist in external objects themselves by making a distinction

between primary qualities and secondary qualities,

(a) Primary qualities: our ideas of primary qualities resemble those

122 Empiricism

qualities as they are in bodies. Primary qualities are size,

extension, shape, movement, solidity.

(b) Secondary qualities: our ideas of secondary qualities do not

resemble those qualities as they are in bodies. Secondary qualities

are hot, cold, sound, colour, taste, odour, etc.

Locke was greatly influenced by the atomic theory of matter

propounded by Boyle; the basic stuff of the natural world consists of

material objects which are made up of an insensible structure or

configuration of atoms or corpuscles which themselves have no

internal structure; these microscopic atoms have only primary

qualities. Locke thinks, however, that the soul is immaterial, although

he does not think it impossible that God could have made thought an

attribute of matter. Macroscopic material objects we perceive appear to

have both primary and secondary qualities, but both qualities at the

macroscopic level depend on configurations of insensible particles

which themselves have only primary qualities. The secondary qualities

we perceive are not in objects as-we-perceive-secondary-qualities to be;

this does not mean the secondary qualities are nothing in objects;

rather, the secondary qualities are in objects some determinate fine

corpuscular structure; our ideas of secondary qualities are a result of

the power of qualities as they exist in objects, as insensible corpuscles,

which produce certain sensations in us. The ideas of secondary

qualities are an effect on us of those qualities in objects as insensible

corpuscles with only primary qualities. The ideas caused in us of

secondary qualities never resemble that which in objects causes us to

have those ideas, but are in objects nothing but a certain configuration

of corpuscles.

Take, for example, the secondary quality red: it is true to say that

object X is red if what is meant is that X has a corpuscular structure

such that under normal conditions it has the power to produce in us

the idea or sensation of red, and thus the object X is seen as red; but it

is false to say that object X is red if what is meant is that red exists in X

in the same way as I have the idea or sensation of red. Locke also

distinguishes a third quality which he simply calls “powers”, which is

the capacity of bodies to cause changes in other bodies such that they

then appear different to us, as when the sun melts wax.

Another way of explaining the distinction between primary and

secondary qualities is through the notion of resemblance and accurate

descriptions. Our ideas of primary qualities can resemble (can be

accurate or correct representations/descriptions of) those qualities as

they are in objects. Our ideas of secondary qualities never resemble

(cannot be accurate or correct representations/descriptions of) those

qualities as they are in objects. This is not to say we cannot be mistaken

about what determinate primary quality an object has; but we can be

right in the sense that the quality exists in the object as the same kind

Locke 123

as that which is perceived. We might misperceive the determinate

shape of X as triangular when it is square, but we are not mistaken that

it really has some determinable shape or other; in this sense our ideas

of primary qualities resemble the qualities as they are in objects. We

will always be wrong about the object having any secondary qualities

if we mean that the secondary qualities ever exist in the object in the

same way as we perceive qualities; secondary qualities do not exist in

bodies in the same way as we perceive them at all. This does not mean

we are incorrect to describe X as red if we mean by this that it has that

determinate corpuscular structure which causes one to have the idea of

red under specific conditions.

God has chosen to connect specific corpuscular configurations in

bodies with the power to produce the specific sensations or ideas we

experience; why a certain corpuscular configuration should produce

just those experiences within us is something Locke regards as

mysterious.

Recent thinking suggests that Locke was not making the distinction

between primary and secondary qualities, but was accepting the

distinction, which he took over from the scientific work of Boyle.

Berkeley objects to Locke’s apparent argument for the distinction that

the primary qualities are invariant and secondary qualities variant

with respect to observers: primary qualities are just as variant with the

changing perspective of the observer as secondary ones. But if Locke

did not try by argument to justify making a distinction between

primary and secondary qualities, then Berkeley’s counter argument is

beside the point. Locke’s chief point in accepting the corpuscular

hypothesis is that it provides an economical unifying explanation of a

great variety of phenomena; and whereas we can conceive of an

explanation of changes in secondary qualities in terms of changes in

primary qualities, the reverse seems inconceivable.

How is Locke entitled to have an idea of, and talk meaningfully

about, the insensible configuration of particles which are too small for

us to experience them, given his empiricism about the origin of all

ideas? Locke’s answer is that our inability to experience such particles

is purely contingent, and did we but have microscopical eyes, we

would see them. Moreover, corpuscular explanations involve

insensible particles which are entities which have properties of the

same kind as, or are analogous to, the properties of macroscopic things

we do experience, namely, primary qualities. We speak intelligibly in

referring to the particles because we have ideas of the kind of

properties they have and therefore understand what we mean by the

words describing them.

Locke’s account of substance, the most fundamental independent

stuff in the world, is subject to different interpretations. On one view

Locke notoriously means by substance “naked substance”, a

something I know not what: a “something”, or substratum in general,

124 Empiricism

beside all the qualities we predicate of objects which “support” all

those qualities. We have ideas of things having various qualities, and

since we suppose that these qualities cannot subsist by themselves, we

suppose there to be a something which they are the qualities of, and

that that something is something beside the qualities themselves. But if

a substratum is imagined to be that which is stripped of all qualities,

one is left not with a special, if mysterious, something, but with an

ineffable nothing. Thus the reason that this substance is not known is

that a propertyless substance is logically or necessarily unknowable.

Other interpretations have suggested that Locke’s remarks

concerning pure substance in general—substratum—are ironic. The

suggestion is that Locke rejects the confused notion of a pure substance

in general and aims to replace such talk with positive talk of

something else, while also wishing to explain how we are led to think

of it as underlying aggregates of sensible qualities. He thinks we are

led to belief in substance through: (a) the grammar of subject-predicate

talk; (b) seeking something to explain the cause of the union of

apparently unrelated aggregates of different sorts of qualities; (c) our

notion that qualities—for example, the yellow, malleable, heavy

qualities of gold—cannot exist separately from something in which the

qualities can exist. Locke’s reinterpretation of substance originates in

substance as the sought-after cause explaining why some particular

substance such as gold should always have the qualities of being

yellow, malleable, and heavy, when there seems to be no connection

between the qualities. The explanation for the connection or union of

these apparently unconnected qualities in all instances of a particular

kind of substance in fact lies in the common real determinate internal

corpuscular structure.

Locke describes the nominal essence of a thing as simply the

qualities or properties we decide to gather under a sortal name, such

as “gold”, for the purpose of classifying particulars into kinds. The

nominal essence gives us a criterion for identification. Although there

are natural constraints on us, the sorting of things into kinds in this

way is created and linguistic.

Locke talks of real essence in two senses. First, the traditional

scholastic sense of real essence as a thing’s substantial form which

makes a thing the kind of thing it is; Locke rejects this as obscure and

having no explanatory use; to explain the properties of gold by saying

that it has those properties because it possesses the substantial form of

gold is just to say gold has the properties of gold; talk of substantial

forms stops us seeking the underlying causes. Talk of underlying

causes refers us to Locke’s second sense of real essence; that is,

Lockean real essence which is the real determinate internal

corpuscular constitution on which the apparent properties depend.

We cannot strictly know the inner atomic structure of things because

our senses are not fitted to perceive them; nevertheless, the notion,

Locke 125

unlike substantial forms, is an intelligible hypothesis which has

genuine explanatory power. Moreover, our lack of knowledge of the

inner atomic constitution of things is, unlike the lack of knowledge of

“pure substance in general”, merely a contingent matter.

Locke defines knowledge as “nothing but the perception of the

connection and agreement, or disagreement and repugnancy, of any of

our ideas”. Propositions are true when the ideas constituting the

propositions are connected in such a way as to make them true; we can

know propositions to be true in so far as we can “perceive” this

connection. Add to this the condition that knowledge must be of truths

that are certain and universal, and what we can be said strictly to

know turns out to be extremely meagre. But we are not left only with

doubt where we cannot have knowledge since we can also have

probable belief. Locke’s overall aim is to commend to us the view that

the lover of truth should not hold a proposition more firmly than the

proof or evidence for it warrants. Locke lists four sorts of agreement

and disagreement of ideas.

(1) Identity or diversity

Here he seems to have in mind logical identity and contradiction.

(2) Relation

Here he is referring to demonstrative logical or mathematical

relations.

(3) Coexistence or necessary connection

Here is meant connection of ideas which reflect the manner of

connection of properties of things occurring together in nature.

(4) Real existence

Here he means what really exists in the world.

Our limited ability actually to perceive the appropriate connection

between ideas in a large range of cases immediately restricts what we

can know, strictly speaking. There is no problem in claiming to know

as true propositions whose ideas can be immediately perceived as

connected or disagreeing, such as “blue is blue” or “blue is not

yellow”; these are intuitive truths. Such truths Locke refers to as

trifling. Locke more dubiously claims some moral truths can be known

intuitively. There is also little difficulty in making a plausible case for

our knowing truths which result from logical deductive reasoning,

such as geometric and mathematical truths, which can be thought of as

made up of intuitive steps or connected chains of intuitive truths

which form the process of demonstrative reasoning. After this

difficulties arise.

Locke himself admits that to have an idea is one thing, but it does

not follow, when not actually receiving the idea, that anything exists

corresponding to that idea. The problem is the lack of any connection

to be perceived between our having an idea and the real existence of

that which the idea is an idea of. A possible exception is the existence

126 Empiricism

of God and that the idea of God entails that God is—which amounts to

a compressed ontological argument. Locke equivocates on what we

can be said to know exists. He thinks that we have intuitive knowledge

of our own existence; he thinks that we can have demonstrative

knowledge of God’s existence; and he thinks that, while we are

actually perceiving objects, we have a belief of such great assurance

and certainty that those objects exist without us that it “deserves the

name knowledge”. He is clear, however, that strictly speaking we

cannot know the truths expressing actual factual connections between

the properties we experience objects to have or know the scientific

hypotheses with which we describe their behaviour (for example the

connection of the idea of “gold” and “soluble in aqua regia” in the

proposition “Gold is soluble in aqua regia”); we cannot know truths in

these cases because we cannot perceive any intrinsic connection

between the constituent ideas reflecting those properties such that it

would make them true; we cannot perceive any necessary connection

between the ideas; all that we perceive is the juxtaposition or

conjunction of the ideas. So in the case of natural science we are not

capable of knowledge, but we can believe with some degree of

probability in the truth of scientific propositions, and the probability of

truth will increase in proportion as it conforms to my past experience

and that of others.

Locke’s view suggests a hierarchy of certainty, here given in

descending order of certainty:

(A) intuition

(B) deductions or demonstrations

(C) sensitive knowledge

(D) natural science.

(A) and (B) strictly constitute areas of knowledge; (C) is knowledge of

the existence of particular objects in the external world as we actually

perceive them, although it is not so certain as (A) and (B); but with (D)

we have only probable belief. Knowledge of our own existence is

included in (A), and that of the existence of God in (B). With these

exceptions, Locke is in danger of leaving us with knowledge almost

entirely of propositions which are hypothetical non-existential (stating

what follows if we accept certain propositions, regardless of whether

those initial propositions are actually true) and verifiable a priori, and

little knowledge of propositions which are categorical existential

(asserting the actual existence and nature of things) and verifiable a

posteriori. There is certainly a problem in claiming to know the general

or universal existential propositions and the existence of objects not

actually perceived which are required for natural science. In short,

knowledge is restricted to necessary certain truths, in which case

knowledge is limited to logical relations and excludes relations of fact

which are neither necessarily nor certainly true.

Locke 127

Locke is Cartesian, or at least rationalist, in giving a necessitarian

account of reality: knowledge of reality would ideally be one of

revealing the natural necessity and connection of things. He differs

from the rationalists in his scepticism over whether natural necessities

can actually be known; but he also differs from empiricists in holding

that there nevertheless are natural necessities—necessities between

matters of fact about the world—which could be known. Thus he does

not fit the traditional empiricist mould for two important reasons:

(a) Locke does not share the empiricist view that all knowledge

which we can know independently of experience by reason

alone is thereby trivial and unable to tell us anything about the

actual nature of reality. Mathematical and geometrical truths are

cases of non-trivial a priori knowledge in which we discover

new truths.

(b) Locke believes, unlike Hume, in natural or metaphysical necessity.

The epistemological problem that we cannot know natural

connections to be necessary and with certainty does not show the

necessary connections are not there. Locke says in addition that

our inability to perceive the connections as necessary is a purely

contingent matter which depends merely on our inability to

perceive the inner microscopic corpuscular structure of material

objects; could we see this structure, we would perceive that the

connection between the qualities objects have is necessary. If we

could see the microscopic structure, we would see that the

sensible qualities or properties of X which depend on that

microscopic structure must occur together necessarily.

Locke does not see the problem Hume uncovers, that no matter how

acute our senses we would only ever perceive one idea A in

conjunction with, or followed by, another idea B, but would never

perceive between them a necessary connection such that B must be in

conjunction with, or must follow, A, and things cannot be otherwise. If

the connection were necessary, then the assertion of (A and not-B)

would be a logical contradiction, but it never is when describing actual

matters of fact. There is no analogous connection between natural

matters of fact for necessary deductive connections or logical relations.

It is never a logical contradiction to suppose that A occurs, but B does

not follow, or that property A is not found with property B, no matter

how many times the conjunction of A and B has been observed.

Necessity based on logical contradiction is the only sort possible. The

universal generalization “All A is B” and the necessary causal

connection “If A occurs, then B must occur”, where A and B describe

matters of fact, cannot be known to hold, or the beliefs rationally

justified, through the evidence of experience or by deductive

reasoning; thus they cannot be known or rationally justified at all; this

is the logical problem of induction and causation.

128 Empiricism

Berkeley

George Berkeley (1685–1753) was born near Kilkenny, Ireland. At the

age of fifteen he entered Trinity College, Dublin, and graduated with

his BA in 1704 at the age of nineteen; he became a fellow of the College

in 1707. The spur to his philosophical writing probably derived from

reading Locke, Newton (1642–1727), and Malebranche (1638–1715).

Berkeley’s New theory of vision appeared in 1709, with a fourth edition

in 1732. His major philosophical works, A treatise concerning the

principles of human knowledge (1710) and the Three dialogues between

Hylas and Philonous (1713), were both published by the time he was

twenty-eight. In 1724 he resigned from his fellowship to become Dean

of Derry. In 1728 Berkeley left, with his wife, for America in an attempt

to found a college in Bermuda to educate the native Indians and the

sons of local planters, but the money for the project failed to

materialize from the government in England. Thus in 1731 Berkeley

returned to England, and eventually to Ireland where he became

Bishop of Cloyne in 1734. In 1752 he moved to Oxford, and died there

suddenly in 1753 at the age of sixty-eight.

It is perhaps more than usually necessary in understanding the

philosophy of Berkeley to place it in its intellectual context; otherwise

Berkeley’s philosophy can seem too obviously false to require serious

examination; his philosophy has been called immaterialism or

idealism, although the two terms are not exactly equivalent.

Berkeley exemplifies one way of stringently applying empiricism:

he conjoins the view that all we can ever know is our immediate ideas

with the view that words and other expressions in our language derive

their meaning only from association with specific ideas; this leads to

the ontological doctrine that only ideas subsisting in minds and minds

themselves can be said to exist because to talk of things existing in any

other way is meaningless as the expressions used in the talk are

necessarily unconnected to any ideas. Expressions not translatable

into, or associated with, some experience are meaningless.

The essential background to the understanding of Berkeley’s

philosophy is formed by a combination of the new scientific

materialism and the representative theory of perception. Scientific

materialism, mainly derived from Newton, proposes a mechanistic

conception of the universe which functions like the works of a giant

clock and a corpuscular hypothesis as to the constitution of matter. The

representative theory of perception, mainly derived from an

interpretation of Locke, is here the thesis that the immediate objects of

perception are always ideas. There are also connected problems arising

from Descartes and Malebranche concerning the relation between the

incorporeal mind and the corporeal body. Berkeley saw the scepticism

that could arise from these beliefs as a scandalous affront to common

sense and a threat to religious belief; but all the forms of scepticism,

Berkeley 129

Berkeley thinks, can be eliminated at one blow by rejecting their

common assumptions.

The scepticism to which the materialistic philosophy gave rise took

three main forms:

(a) the existence of sensible things

(b) the nature of sensible things

(c) the existence and nature of God.

The main additional sceptical problem posed by Cartesianism is:

(d) how matter and spirit can interact.

Materialism gives rise to all the first three forms of scepticism when

combined with the doctrine that we only ever perceive immediately

ideas in our minds by opening an unbridgeable gap between how things

appear to us and how they really are in themselves: a gap between our

ideas and what our ideas are ideas of. Material objects, specifically their

corpuscular structures, are seen as the cause of our ideas; but material

objects do not have, in the same way that we perceive them, all the

qualities that they appear to have. The gap between the ideas that we

immediately perceive and their supposed causes, which we do not

directly but only ever mediately perceive by way of ideas, opens up the

possibility of an insoluble scepticism concerning our knowledge of the

nature and even existence of the objects of the external world. We can

never gain immediate access to the something, whatever it is, that is the

cause of our ideas to check whether the ideas which supposedly

represent the nature of that something are accurate, or even whether the

supposed something exists at all; we can never perceive the something

that is the supposed cause of our ideas immediately but only mediately

in virtue of perceiving immediately intermediate mental objects: ideas.

Materialism also leads to atheism according to Berkeley, since the

posited material substance is to a high degree, or perhaps completely,

independent of God in its operations and existence. Many materialists

supposed that God was ultimately still required as the creator and first

mover of the universe; but if we suppose that the universe has existed

for ever, then God’s existence again becomes dispensable. The existence

of God is still possible, but His existence is not logically required, nor

even obviously important.

An additional, but connected, source of scepticism derives from

Descartes and Malebranche. In the Cartesian view there are two

distinct substances, mind and matter, whose essential attributes are

thought and extension respectively. The problem then arises as to how

their interaction is to be made intelligible: how can the non-extended

mind cause changes in motion of extended bodily parts, such as the

brain, and how can motions of the extended bodily parts cause

changes in non-spatial mental substance which produces thoughts?

This problem led Malebranche to the doctrine of occasionalism: this

130 Empiricism

holds that although mind and body do not interact, God on the

appropriate occasions systematically intervenes to produce the same

result as if they did interact; on the occasion of my willing the

movement of my body God causes the correct bodily movement; on

the occasion of my observing a physical object God causes me to have

the appropriate perception by sharing in His ideas.

Berkeley thinks that materialism is:

(i) Unjustified

The arguments presented for the adoption of materialism are

insufficient,

(ii) Unnecessary

The thesis is extravagant since it posits the existence of material

entities that are not required to give an explanation of the course

of our experiences,

(iii) False and must be false

Matter is not, and indeed cannot be, the cause of our experiences,

(iv) Meaningless

It requires us to give meaning to the term “matter” or “material

substance” which is something we never directly experience,

which is the cause of our ideas; but as the meaning of a term is

the idea for which it stands, and there can be no idea of that

which we cannot experience, then all terms referring to entities

such as material substance, which are beyond experience, must be

meaningless,

(v) Contradictory

It requires that ideas may exist when not perceived by us in an

unthinking corporeal substance or matter.

In several important ways Berkeley is a very strict empiricist. Generally

he holds that the limits of what it is intelligible or meaningful to talk

about must refer to something in the content of our experience. If we

are making some distinction in the world, it must, to be genuine, refer

to some perceivable difference; if a proposition is intelligible, it must

refer to something perceivable. It is surely part of the persuasiveness,

even attractiveness, of Berkeley’s idealism that it asks us to concentrate

only on the actual character of the content of our own minds.

Berkeley’s overall strategy in opposing all the forms ((a), (b), (c), (d),

above) of scepticism derives from closing the gap between our ideas

and what our ideas are ideas of; thus preventing the sceptic from

driving a wedge between the two. Berkeley advocates negatively

immaterialism and positively idealism; he also assumes that if

materialism can be shown to be false, then his form of idealism must

be true in virtue of its being the only alternative to that materialism.

Talk of material objects, in Berkeley’s philosophy, is not a reference to

some material substance which can exist unperceived as the supposed

cause of our ideas but which, since the objects of perception are always

Berkeley 131

ideas, we never actually perceive. To talk of material or sensible objects is

to talk about actual or possible objects of perception, and that is to talk of

ideas or bundles/collections of ideas themselves which must, as ideas,

exist in a mind or spiritual substance. To talk of material objects or

sensible things is not to refer to something other than the ideas we

perceive, it is to talk of those ideas themselves; what we mean by

material objects is just certain ideas or sets of ideas. Any reference to the

nature or character of the world is a reference to, and is only intelligible

as a reference to, actual or possible experiences. What we immediately

perceive in vision is a flat, two-dimensional array of colours and shapes.

In the New theory of vision Berkeley presents arguments to show that

distance is not something immediately perceived but something

constructed from certain orderly relations of the ideas of different senses

in the mind. Thus to say an object is one mile away is just to say that a

certain sequence of ideas—for example, those constituting the experience

of walking forward—would have to go through the mind before we

received such-and-such ideas of touch. This lays the groundwork for the

view that what is perceived (the object of perception), because it is in no

case an immediate perception of something at a distance from us, is

therefore always something in the mind.

The equating of ideas with sensible things, which thereby makes

sensible things mind-dependent, eliminates each of the previously

mentioned forms of scepticism ((a), (b), (c), (d), above) produced by

materialism and Cartesianism in the following way.

(a) The existence of sensible things. This problem is eliminated

because the sceptic cannot drive a wedge between ideas and

things; if the objects of sense are ideas, and we cannot doubt that

we have ideas and thus ideas exist, we cannot doubt the existence

of the objects of sense or sensible things.

(b) The nature of sensible things. This is just the sum of a thing’s

sensible qualities. In addition science no longer purports to reveal

the essential nature of things in the external world whereby it can

establish the necessary connections required for true causal

relations between the sensible properties of things we can

perceive; rather, it aspires only to map the regular correlations

between ideas, that is, between phenomena.

(c) The existence and nature of God. This problem is eliminated by

making God metaphysically indispensable: once material

substance is eliminated, it is necessary to affirm that God exists as

the immediate real cause of those ideas that are not caused by our

imaginations and as the sustainer of those ideas we do not

actually perceive; thus God’s existence is manifest at all times as

the immediate cause of the vast majority of that which we

experience; the supposition that God does not exist is refuted by

almost every experience we have.

132 Empiricism

(d) How matter and spirit can interact. This problem is eliminated by

denying the existence of material substance; then the problem of

interaction between spirit and matter simply does not arise.

Berkeley also rejects occasionalism, arguing that we cause those

ideas which constitute what we can legitimately will, such as

moving our legs.

Berkeley presents various arguments opposing materialism.

(1) Berkeley thinks that the conception of matter as really having only

primary qualities, such as extension, shape, solidity, movement, is

an impossible one; he questions whether it is possible for us to

conceive of a shape which is no colour whatsoever; the conception

of matter required for materialism is impossible, for it involves

matter devoid of all secondary qualities, which are types of

qualities which it could not lack, and from which primary qualities

cannot be separated.

(2) Berkeley argues that it is a logical contradiction to talk of

conceiving of a thing which exists unconceived, for to conceive of

the possibility of something existing unconceived is necessarily to

conceive of that thing. But this argument, although tempting, is

fallacious. It is true that it is not possible for A to be conceived of,

and at the same time both exist and be a thing unconceived; but

that does not mean that at some other time A could not exist as an

unconceived-of-A; thus there is nothing contradictory in A

existing unthought about.

(3) Berkeley turns Locke’s argument concerning the relativity of

perceptions against Locke’s materialism. Berkeley takes Locke to

be arguing for the distinction between primary qualities (shape,

size, motion, solidity) and secondary qualities (colour, taste, heat,

sound, etc.) on the basis that those qualities, not really in objects

as we perceive them to be, are those that vary with the

disposition of the perceiver; such qualities are, as they are

perceived, subjective or in the mind (Locke does not in fact argue

that secondary qualities are therefore merely subjective) and result

from the effect of the insensible particles on us. But Berkeley

points out that if this argument proves that secondary qualities

are ideas in the mind, the same argument proves that primary

qualities are also only ideas in the mind, for these too vary with

the observer. In fact, there is no reason to suppose that in either

case we have shown the qualities to be subjective, for there is no

reason to believe that for a kind of quality to be really in objects,

or be attributed as a real objective property of objects, it must be

invariant with all changes in the observer. Moreover, we would

actually expect the real properties of things to vary with the

observer; for example, size as we get closer to an object.

(4) This argument concerns pain and heat. When we approach a fire

Berkeley 133

closely the heat is felt as a pain in the mind; when we are at a

further distance from the fire the heat is felt merely as warmth.

We are not tempted to say that the heat felt as pain is in the fire;

so we should also say the same for the lesser degrees of heat felt

as warmth, that heat is an idea in the mind.

(5) In this Berkeley runs together the notion of matter with what

Locke has to say about substance in general. He attributes to

Locke an account of substance which he thinks unintelligible, and

then takes this to be Locke’s account of material substance or

matter, so that is also unintelligible. Locke’s discussion of

substance in general seems to suggest that it is characterized by

being the “support” of all qualities; the qualities cannot subsist

alone, so substance is that in which the qualities subsist. But if

substance is the support of all qualities whatsoever, then any

attempt to give it a positive characterization is impossible, since

to do so would be to attribute qualities to it; thus substance

becomes an unknowable qualityless “something”. While this

argument is perfectly flawless as an attack on a qualityless

substratum, it is wide of the mark as an attack on matter because

no materialist would suggest that matter is qualityless.

The general form of Berkeley’s positive argument for idealism is as

follows. Sensible things (ordinary objects) are those things perceived by

the senses, and those things perceived by the senses are ideas. It follows

that sensible things are ideas or collections of ideas. In addition, ideas

can exist only if perceived by minds. With this additional premise it

follows that sensible things cannot exist unperceived.

Repeatedly Berkeley asks how the supposed “material substance”

should be characterized: what qualities or properties does it have?

Indeed any concept, apart from that of mind, if it is to be given a

meaning at all, must be translated into talk about some possible or

actual experiences. Whatever is suggested as the nature of “material

substance”, he points out that, if we can make what we are talking of

intelligible at all, the quality referred to is something that we

experience; but what we experience immediately is ideas, and hence

the existence of the quality is as an idea in the mind; and if we refer to

something that we do not experience, then he does not understand

what we mean when we refer to it.

Berkeley makes a distinction between immediate and mediate

perception; respectively between the immediate sensations of the

various senses, which involve no inference and about which we cannot

be mistaken, and that which is suggested by these perceptions. The

proper objects of perception are strictly speaking only those things we

perceive immediately, and all else that we claim to perceive is a

construct or inference from immediate perceptions.

Thus Berkeley identifies the normal everyday objects or sensible

134 Empiricism

things that we talk about with ideas or bundles of ideas; but in making

things into ideas he thinks he can show that he has not made them any

less real. Berkeley’s idealism is opposed only to the philosopher’s

conception of material substance as that in which sensible qualities

that we perceive through the mediation of ideas subsist when we do

not perceive them. Berkeley concludes that the very meaning of saying

that sensible objects exist is that they are perceived—although at times

he suggests that an object’s existence consists in its being perceivable.

Berkeley moves from the commonsense belief that sensible things are

simply what we perceive, to idealism which holds that the existence or

being of sensible things consists in their being perceived or at least

perceivable. In the end Berkeley holds to the view that to be or exist as

a sensible object is to be actually perceived, and not to the

phenomenalist view that to be is to be perceived or perceivable—to be

perceivable is to exist as a mere permanent possibility of sensation.

Thus, in Berkeley, with respect to sensible things, esse est percipi: to be is

to be perceived. This is not the only meaning that can be given to

existence, however: minds or spiritual substance, which have ideas,

also exist. To exist is thus also to perceive: esse est percipere: to be is to

perceive or be a perceiver. So in full we can say esse est aut percipi aut

percipere: to be (exist) is either to be perceived or to perceive. Spirits are

not, like sensible things, constructed as phenomena out of perceived

collections of ideas; they are that substance in which ideas inhere.

This position might seem to suggest implausibly that when sensible

things are not perceived by us they cease to exist: that they would

come and go out of existence. This would be true if only our own or

only human minds did the perceiving. But Berkeley’s view is only that

to exist is to be perceived by some mind or other. This is part of God’s

place in Berkeley’s world, although strictly speaking God does not

perceive ideas since He lacks senses, He nevertheless sustains in

existence by His mind those ideas of sensible objects not actually

perceived by us. Ideas that do not subsist in our finite minds subsist in

the infinite, omnipresent, omnipotent mind of God. God is essential to

Berkeley’s system; and if the system is true God is indispensable to all

of us. God is required for two main reasons. First, God is required to

give the continuity of a sustained existence to sensible things

unperceived by us. Second, God is required as the cause of those ideas

we experience which are not caused by us. The only entities capable of

being real efficient causes are minds, which alone are active as they are

capable of willing; ideas themselves are inert and incapable of being

real efficient causes. Berkeley agrees with Locke that causality can only

be understood through the experience of willing, but goes further in

saying that the only intelligible cases of causation are those that

involve willing. We are to a limited extent capable of creating ideas

through the faculty of imagination, but most of the ideas we have are

not caused by us; they must therefore be caused by some other mind;

Berkeley 135

nothing but the infinite mind of God could account for the richness,

stability and orderliness of the ideas we perceive. God directly causes

us, without the unnecessary mediation of any material substance, to

have those ideas which we call ideas or perceptions of sensible things,

which are those ideas not caused by ourselves.

Berkeley maintains the distinction between perception of reality and

the imagination, and denies the suggestion that he has turned the

world into mere fancy. Initially the distinction is made by pointing to

those ideas that come before our mind that are not products of our will

and imagination; these ideas are ideas of reality and have some other

cause, and that cause is God. In short, the real is characterized by being

those ideas caused by God. However, dreams also are involuntary

although caused by us. Also the problem remains of how we identify

which ideas are God-caused. There is, argues Berkeley, a greater

strength (force and vivacity), order and coherence among ideas we

refer to as being of reality.

There remains too the problem of distinguishing veridical

perceptions from illusions. A stick appearing bent in water is a genuine

perception, since it is not caused by us; it is an illusion, not in isolation,

but in virtue of its relation to the sequence of other ideas we have, such

as whether it is followed or not followed by the experience of a

straight stick if we feel the stick in the water or the sight of a straight

stick if we take it out of the water.

Berkeley seems to say there is an “archetype” (original) idea in the

mind of God which God wills us to perceive. We perceive ideas as well

as imagining ideas. God imagines and wills ideas only; if this were not

the case, we would have to posit an infinity of Gods as the cause of

each other’s perceptions. God wills that we perceive “ectypes” (copies)

of aspects of the archetype ideas in His mind. The notion of two or

more people perceiving the same thing, although their ideas may be

qualitatively different, seems to depend on there being a common

archetype.

We can summarize Berkeley’s ontology in the following way:

136 Empiricism

Reference here to “Minds”, of course, includes the mind of God.

Berkeley’s idealism claims not to question the truth of the

judgements of common sense; rather it claims to affirm them and to

make clear what affirming those truths really means. Berkeley’s world

will appear exactly the same as the world containing matter; it makes

no difference to the course or order of our experiences. Nevertheless

Berkeley’s world is different even if it looks the same.

This brings us to Berkeley’s views on the meaning of words or

terms. The meaning of terms is the ideas for which they stand; if

there is no identifiable idea corresponding to, or associated with, a

term, then it is meaningless; if the term has a meaning at all, it must

refer to some feature of experience: to a particular idea or collection

of ideas.

This leads us to examine Berkeley’s objection to abstract ideas as the

meaning of general terms. Locke had suggested, according to Berkeley,

that it was possible to form abstract ideas from particular ideas and

that this explained the meaning of general terms and their ability to

apply to any particular of a class of particulars similar in some respect;

thus we form the abstract idea of triangularity, which is what the term

“triangularity” stands for, and so it applies indifferently to every

triangle. A general term such as “man” applies to all things of the same

kind, namely men. The abstract idea applies indifferently to all

particulars of a certain class by virtue of including only that which all

the particulars have in common and nothing in which they differ.

Berkeley thinks that Locke’s notion of our forming abstract ideas is

both impossible and unnecessary. It is impossible because the process

of abstraction involves separating qualities that cannot be separated,

and running together qualities that are incompatible. In the case of

triangularity we have to separate off just the property of being a

triangle from that triangle being, for example, any particular or

determinate size or colour; it is also an idea of a triangle which is no

particular kind of triangle, so it must, to be general, be an idea which is

at once all and none of the differents kinds of triangle. Berkeley thinks

that we cannot form such an idea. Abstract ideas are unnecessary

because terms can be general without their meaning deriving from

their standing for abstract ideas: terms become general through their

being used to stand for a class of particulars which are similar in some

relevant respect.

The connection of this with Berkeley’s objection to materialism is

that he sees the route to positing material substance as dependent on

the possibility of abstraction. If we can form abstract ideas, it is

possible to argue that we can speak meaningfully, through the

formation of an appropriate abstract idea, about something that exists

which is not, and could not be, an actual object or content of

experience; we can thereby give meaning to terms such as “matter” or

“material substance” and so refer to something other than what we can

Berkeley 137

actually experience—which is particular ideas—and then posit its

existence independently of its being perceived. If Berkeley has shown

that abstract ideas are impossible, and if abstract ideas are required to

give meaning to terms such as “matter” or “material substance” which

refer to that which can exist unperceived, then he has shown that all

talk of matter or material substance in this sense is meaningless or

unintelligible.

Berkeley is, however, strangely inconsistent in his empiricism,

since he sees fit to talk, and claims to talk meaningfully, about mental

substance and God, of both of which we can never actually have

ideas, so talk of them should strictly be meaningless. Ideas can only

be like other ideas; ideas are passive or inert whereas minds are

active; ideas are thereby debarred from representing spiritual

substance. Berkeley tries to get round this by claiming that although

we cannot, strictly speaking, have ideas of spirit, we can have a

notion of it. He intends by this to contrast spirit with matter: whereas

the latter has been shown to be impossible or contradictory, mind is

at least possible and intelligible, and we can therefore form some

notion of its operations.

The only sense that Berkeley gives to causation is that of active

willing. Ideas themselves are inert and passive, incapable of willing,

and therefore incapable of causal influence. The supposed material

substance in which qualities are said to inhere is also lifeless and

passive, and would therefore be incapable of causal influence. Only

spirits are active; it follows from this that the cause of all ideas must be

some spirit or mind. Some ideas are caused by our own finite minds,

as when we imagine ideas; but the vast richness of our other

experiences must be caused by the infinite mind of God.

When it comes to his analysis of natural science, in particular

physics, Berkeley’s views find powerful echoes in modern

instrumentalism. Berkeley argues against essentialism in physics:

essentialism suggests that beyond the phenomena or appearances that

we observe, the phenomena are caused by and united in an ultimate

reality whose essential nature (such as atomic structure, extension, or

substantial form) finally explains all phenomena and the necessary

connection between phenomena observed to be constantly conjoined.

This necessary connection takes the form of logical deducibility. The

positing of some kind of essential nature is required to give a

foundation to unifying causal laws which are the characteristic aim of

science. A causal law of the form “If A then B”, or “All As are Bs” does

not merely describe the accidental juxtaposition of A and B in our

experience, but aims to identify a necessary connection between A and

B such that we say if A happens, then B must follow, and if something

is A, it must also be B; in short A and B are connected in a way that

could not be otherwise. That there exist such necessary connections

between ideas we experience is denied by Berkeley; no such necessary

138 Empiricism

connection is perceived between phenomena. There are no essential

natures in things beyond experience; indeed, it is senseless to posit an

essential nature in a reality of things beyond phenomena which would

account for the necessary connection of our ideas; all that we ever

experience is a succession of ideas among which we perceive patterns,

associations and regularities. The search for such unattainable

necessary connections only breeds scepticism about the achievements

of science when science fails to show that it can establish how the

world must be. Scientific theories do not present us with the truth

about reality—metaphysics and theology do that—rather their value

lies in their usefulness as general rules by which we can predict

phenomena: what ideas will follow what, and what ideas are

invariably found together. By limiting the aspirations of science

Berkeley hopes to secure science from scepticism, and at the same time

make room for the indispensability of theology.

Ideas are seen by Berkeley as natural signs; the experience of idea X

is a sign that idea Y is about to follow; and it is our job to learn what

these regularities are and to come to know the rules which correctly

map the patterns of ideas; but we must not suppose that we have

thereby discovered necessary connections between the ideas that could

not be otherwise. That the ideas follow each other in regular order is

entirely dependent on the will of God who chooses to present to us

ideas in definite regular patterns, the rules of which we can learn. In

learning the order of natural signs in science we learn the “language of

God”: the signs He systematically presents us with. The experience of

getting closer to a fire will be followed by the experience of pain; but

the two experiences are not necessarily connected; the relation

between the two experiences is contingent; there is nothing about the

experiences themselves, or about any further thing which is the cause

of the experiences, which means that the juxtaposition of the

experiences could not be otherwise. Yet we can trust in God that He

will invariably maintain a regular order which it is possible for us to

learn. In this way science is seen merely as a more systematic attempt

to chart our experience than our everyday understanding, but not

different in the kind of knowledge it produces.

It is, however, not true to say that Berkeley gives a regularity theory

of causation. Although the mapping of regularities between noncausally

associated ideas is the aim of science, real efficient causal

influences take place between spiritual substances and ideas.

On Berkeley’s view, the use in science of various terms such as

“force”, “gravity”, “attraction”, “cause”, “effect”, and “insensible

particles” is harmless provided we do not think that these terms name

real entities in the world which explain the causal necessary

connection of phenomena or events we experience; such terms should

be seen as merely useful suppositions or hypothetical posits which

may aid us in making predictions. They do not describe facts about the

Berkeley 139

world; but we can use them to help us predict phenomena; the

phenomena can be understood as occurring as if they were facts about

reality. From the point of view of facilitating the discovery of the

general rules describing the order of phenomena, the truth of what one

supposes as a mechanism is to be valued purely for its convenience,

and its truth is irrelevant, for its truth as a mere useful supposition

does not arise at all. More positively we can say that anti-essentialism

encourages us always to seek further explanations because it does not

assume there will be, and we might find, some point at which

explanations are exhausted and complete.

Nevertheless, the sense in which we can be said to learn the language

of God gives some residual meaning to scientific theories or laws being

true; not every invariable correlation will constitute a law of science;

the use of the terms language and signs suggests a structure that,

although not necessary, does have an order of meaning and syntax

analogous to that of a language.

Many problems reside in Berkeley’s system. It is difficult to see how

his proof that God exists can be valid if based on the premise that ideas

that are not perceived by our minds must, if they are ideas of real

things, continue to exist, and can do so only in the mind of God. No

possible empirical evidence could verify the proposition that the ideas

constituting object A exist unperceived by us. We are precluded from

establishing by experience the ontological continuity of ideas

constituting sensible objects when we do not experience them by the

fact that any attempt to gather appropriate empirical evidence would

be self-defeating: we cannot get a sly glance at things unperceived.

This is rather like trying to determine whether the fridge light goes off

when one closes the door, except that in the case of ideas constituting

sensible objects it is a logical impossibility, not an empirical difficulty

involving empirically determining if things exist unperceived. If the

only guarantee we could have for knowing real things exist

unperceived is following a proof that God exists, then a proof of the

existence of God cannot, without being circular, use as a known

premise that real things exist unperceived when not perceived by us.

The basis for idealism is that all that we ever perceive is ideas or

sensations—light, colours, sounds, smells, tastes and the like—which

can only be conceived of as existing in the mind. It is this that must be

denied in an effective refutation of idealism. We must say that we can

be immediately aware of physical objects in perception; what we

perceive is appearances or aspects of objects themselves, not other

entities called ideas that mediate between us and objects perceived.

If Berkeley were to stick strictly to his empiricism in using as

evidence only the immediate content of our own minds, then it is

difficult to see how he could avoid extreme solipsism: there is nothing

he can be sure of except the nature and existence of the ideas of which

he is immediately or currently conscious.

140 Empiricism

Hume

David Hume (1711–76) was born in Edinburgh, into a family of the

minor gentry near the Scottish Border; the family home was the estate

of Ninewells, close to the village of Chirnside near Berwick. David

Hume’s father died in 1713, leaving his mother to bring up David and

two siblings, of whom David was the youngest. Their religious

education was Calvinist in character with regular attendance at kirk.

Hume entered Edinburgh University in 1723 when not quite twelve.

Here he received instruction in Latin, Greek, mathematics, physics and

philosophy, and became acquainted with the work of John Locke and

Isaac Newton; but he left the university around 1726 without taking

his degree. By this time he had arrived at the atheism that was to last

for the rest of his life. He returned to Ninewells where, following the

family tradition, it was proposed that he turn to law as a profession;

but Hume had no appetite for the law and instead spent time studying

great classical literature. In 1734 Hume entered the offices of the West

India company in Bristol, but his stay here was very short-lived, and

he went to France where he could live more cheaply, first in Rheims,

and then at the small town of La Flèche in Anjou; here he wrote A

treatise of human nature. He returned to London in 1737 and after some

difficulty eventually found a publisher; the Treatise appeared in 1739

and 1740, by which time he had returned to Ninewells. The book did

not receive the high level of attention he had hoped, although he

exaggerated when he said that “It fell dead-born from the Press.” In

1745 Hume’s application for the professorship of philosophy at

Edinburgh University was rejected. From 1747 onwards Hume earned

his living chiefly as a diplomatic secretary, which involved travel

abroad. During this time he continued to publish short essays on

various topics, and began work on the Enquiries concerning human

understanding and concerning the principles of morals, in which he sought

to rectify the presentational and stylistic deficiencies which he thought

had led to the modest acclaim awarded to the Treatise; the Enquiries

was published in 1748. In 1752 Hume became librarian to the Faculty

of Advocates in Edinburgh, having been turned down in 1751 for the

Chair of Logic at Glasgow despite the support of the vacating

professor, Hume’s friend, the economist Adam Smith (1723–90); it was

as a librarian that Hume began his History of England. In 1761 he

became a personal secretary at the Embassy in Paris and was extremely

popular in Paris society. In 1766 Hume returned to England with the

philosopher Jean-Jacques Rousseau (1712–78); however, Rousseau’s

chronic paranoia and unreasonableness soon caused them to fall out.

Hume retired from work in 1769 and lived in Edinburgh. In 1775 he

was struck by a fatal wasting disease of the bowels and he died the

following year.

Hume’s affable disposition while terminally ill was typical of his

Hume 141

general character; he also remained unshaken in his rejection of any

kind of survival in an afterlife. Although lean in his youth, in later

years he had a rotund physique, and he took pleasure in food and

good conversation. Despite having a formidably sharp intellect, he

seems to have had a generally amiable, sociable, cheerful personality.

There is a tension which runs through Hume’s philosophy between

scepticism and naturalism. The sceptical side involves the employment

of various arguments showing that we lack any rational justification

for beliefs usually regarded as fundamental to our view of the world.

There are three beliefs of particular importance that come in for this

treatment:

(a) existence of causation and the rationality of induction

(b) existence of the external world: bodies continue to exist

independently of us in the external world

(c) existence of a permanent self.

In each case Hume sets out to show that we have no rational

justification for the belief, but also how the belief is a fundamental

product of the faculty of imagination in human nature. Hume’s

purpose in revealing the lack of rational warrant is to show the limits

of what human reason can account for. The naturalist strand in

Hume’s philosophy now enters for he does not draw the conclusion

that because we lack rational justification for these beliefs we ought

therefore to reject the beliefs. It is a fact that we do irresistibly,

invariably and universally hold these beliefs, which are the foundation

of thought and necessary for our survival; if our holding of these

beliefs cannot be accounted for through our possessing sufficient

rational grounds for the beliefs, then it is still to be explained why

nevertheless we hold these beliefs, think the way we do, and remain

unshaken by sceptical arguments directed against them. In short, one

possible explanation for why we hold these beliefs is that we have

rational grounds for doing so, but where we do not have rational

grounds there must be some other explanation for why we have these

entrenched beliefs. The explanation is to be found in the science of

human nature. This science reveals that the way we come to form these

beliefs is the same kind of way as other animals form beliefs; it is

therefore quite proper to say that animals reason.

Sceptical arguments or reasoning can operate only against other

arguments or reasons; but given that the explanation of our holding

certain fundamental beliefs or thinking in certain ways is not to be

found in our having reasons at all, the sceptical arguments or reasons

against these fundamental beliefs or fundamental ways of thinking

find no purchase; rational arguments are simply irrelevant. There is no

question that we ought to think differently because we lack rational

grounds in these cases, as the sceptic suggests, since nature,

specifically human nature, ensures that we cannot help thinking in

142 Empiricism

these ways; these ways of thinking are fundamental facts about human

nature which are explained by non-rational laws describing how we go

on or function; the beliefs thus produced are not thereby irrational;

they would be irrational only if we supposed that the explanation of

our having the beliefs is based on insufficient rational justification and

that rational justification is required. We are psychologically

constituted in such a way that, given a certain course of experiences,

we will inevitably come to hold certain kinds of beliefs.

In our philosophical search for the ultimate foundations for our

beliefs we come to see that certain of our most basic or fundamental

beliefs are rationally groundless or unjustified; but we also come to

understand that they are not the kind of beliefs that can be rationally

grounded or justified; therefore the lack of rational justification is not

to be thought of as a deficiency in these beliefs. They are not the kind

of beliefs which we can be rationally justified or unjustified in holding;

so showing there is no rational justification for the beliefs does not

show them to be irrational or confused; rather, they are non-rational,

but beliefs that we must have resulting from the way our natures

fundamentally are. This position can be further defended by pointing

out that if we enter into the process of giving reasons at all and

suppose that it can ever be successfully brought to an end, there must

be some beliefs for which reasons neither can be given nor are

required; justification has to end somewhere.

An analogy may help. If we take the notion of love we can clearly

understand that cases may arise where L giving reasons to M why M

should love L rather than N is simply out of place; it is not that L’s

reasons are bad reasons; reasons of any sort are simply irrelevant and

make no difference; it may just be a fact that M loves N and not L, and

that is an end to it. One might as well argue with a tree that it is

unusually early to come into leaf, or with an avalanche that it is wrong

to fall on villages.

This naturalism has serious consequences for anything like

Descartes’ project for an absolute, non-species specific, objective

conception or understanding of the world based on pure reason, not

on concepts dependent on our contingent biological or psychological

constitution. For it turns out that some of our most basic conceptions

and beliefs are not transcendent and eternal, but depend on

contingent facts about human nature. Descartes supposes that the

fundamental conceptions involved in a truly scientific view of the

world are are either intuitively obvious or rationally justifiable, and

thereby are true universally for any intelligence whatsoever. Hume

argues that these conceptions are dependent on human nature being

what it is and functioning in certain ways, and without a nature

which reacts in certain ways to experience such conceptions or ideas

would not arise at all, since they cannot be derived from or justified

by universal and valid deductive reasoning or experience. Our

Hume 143

fundamental concepts and beliefs, which we apply to, and regard as

real features of, the world, are species-dependent, not nonperspectival

and absolute. That we have an idea of, and belief in,

causality and induction, a belief in external physical bodies and in a

relatively permanent self, depends on our reacting to certain

experiences in certain ways; such ideas are neither a product of the

pure necessity of reasoning nor derivable from passive observation of

the world; our having these ideas depends on experience combining

with the way human nature functions.

The tension between scepticism and naturalism arises from the

uncertainty as to whether any particular case of a belief lacking

rational justification should lead us to reject the belief or lead us to

conclude that it is vain and unnecessary to ask for justification. The

answer would seem to involve assessing how fundamental the belief is

to human nature; that is, to what extent it is universal, irresistible and

permanent.

Hume maintains the view common to other philosophers of his

period that we are only ever immediately acquainted with the contents

of our mind: perceptions. He divides perceptions in the mind into

impressions and ideas. These are to be distinguished not by their origin,

but by their degree of force and liveliness; impressions are lively

perceptions or experiences and ideas less lively. Impressions are the

primary or first appearance in the mind of any mental content, ideas

are secondary and derivative weaker copies of impressions. Roughly

the distinction is between actually experiencing X, and thinking about

X. Fundamental to Hume’s philosophy is that ideas, which are,

generally speaking, the materials of thought, are faint copies of

impressions and that we cannot have a simple idea of which we have

not had a simple impression. Every simple idea has a corresponding

simple impression that resembles it, and every simple impression a

corresponding idea; that is, every simple perception appears both as

impression and idea. This account has the odd consequence that to

think about X (say, a pain) is mildly to experience X (a pain), which is

surely false. We can have complex ideas of which we have no

corresponding complex impressions, but only if they are made up of

simple ideas copied from simple impressions we have had. The reason

for this view is that Hume wishes to identify the correct impressions

from which we derive ideas. There are two possible sources of ideas:

impressions of sensation and impressions of reflection. Impressions of

sensation are basically sense-experiences; impressions of reflection are

often new impressions which derive from the natural way we react to

certain impressions of sensation. If we have an idea which is derived

from an impression of reflection in this way, then the existence and

nature of the resultant idea partly depend on the workings and nature

of our mind, and the idea is not something derived wholly passively

from experience of the world. The question is whether we are then

144 Empiricism

justified in regarding the resultant idea as corresponding to a real

feature of the world, or whether the idea does not correspond to a real

feature of the world since it is simply a product of the way we react

naturally to certain impressions of sensation, which in themselves do

not contain that idea. For example we find that the idea of evil and evil

acts is not derived from anything observed purely in acts, but results

from the impression of reflection, abhorrence, we naturally feel, because

of the reaction of human nature, at seeing certain acts; that we then

regard evil as really in the world, and certain acts as abhorrent, results

from the idea of evil being projected onto certain acts in the world,

although it is not derived from something observed passively as really

being in the world. If we did not react in certain natural ways to

produce these impressions of reflection we would not, from observing

the world, find any passive impressions of sensation from which the

idea of evil could derive.

The meaning of a term is to be found in associating the term with

the correct idea. If we cannot find any impression of either sensation or

reflection as the origin of an idea which is presupposed in the

corresponding term having meaning, then we must conclude that we

are deluded when we say we have the idea, and the term which

publicly articulates the supposed idea is in fact meaningless. But we

must look carefully; if we cannot find an impression of sensation

(perceptions of red, chairs, mountains, as well as sensations such as

hot, cold, pain) we may well find an impression of reflection (feelings,

passions, emotions, basic appetites, such as anger, sadness, hunger)

from which an idea we have derives; but this has the important

consequence that the true meaning and implications of the term

corresponding to the idea may be quite different from what we

thought them to be. We will have to conclude that if an idea derives

from an impression of reflection or inner sentiment only, then it is not

an objective feature of the world, but one that depends on our natural

propensity to react to experiences in certain ways according to our

human nature.

Hume distinguishes between memory and imagination on the basis

of the distinction between impressions and ideas. Memory: the order/

sequence and combination of ideas is the same as the original order/

sequence and combination of the impressions. Imagination: the order/

sequence and combination of ideas can be different from the original

order/sequence of the impressions.

The imagination is of fundamental importance for Hume’s account of

why we have the beliefs we do have. The order/sequence and

combination with which ideas feature in our imagination is not

random but has rules governing that order; there are forces of

attraction, which, although not intrinsic to the ideas by themselves,

govern the way simple atomic ideas and complex ideas are associated

as a result of fundamental propensities of human nature.

Hume 145

Hume argues that all perceptions are really distinct from each other;

they can exist at different times; they can thus be conceived existing

separately without any contradiction; therefore any connection, if it

exists at all, between perceptions is contingent and not necessary. It is

the human mind that, according to certain natural propensities,

associates perceptions which have logically distinct existences and

between which no necessary connections are ever discovered by

reason or observation; but it is from this feeling of being determined to

associate ideas in certain ways, which is an impression of reflection,

that the idea originates of the perceptions themselves being necessarily

connected.

Hume sees part of his function as explaining why we hold certain

fundamental beliefs; this he does through discovering and calling

upon the laws governing the order of perceptions in our minds. The

basis of Hume’s explanation is the “principle of association of ideas”;

this explains why we in fact think as we do, although we may have no

rational justification for doing so. Ideas become associated in our

minds in specific ways and this controls the order or sequence of

thoughts through our minds. There are three main factors that

determine which ideas are associated in the human mind:

(i) resemblance: qualitative similarity

(ii) contiguity: proximity in space and/or time

(iii) cause and effect: the thought of one idea leads to the thought of a

causally connected idea.

The mind naturally moves smoothly from one idea to another in

accordance with these principles of association. If we have an

impression of A, or entertain an idea A, we naturally move to the idea

B related to it in the highest degree by some or all of the above

principles. Ideas are mental atoms among which Hume attempts to

describe the rules governing their behaviour.

The objects of human understanding and inquiry fall into two

exclusive and exhaustive classes. The distinction is sometimes called

“Hume’s fork”: this contends that all meaningful propositions can be

divided into one of two types:

(I) relations of ideas

(II) matters of fact and real existence.

All propositions of type (I) concern the abstract relation of ideas, and can

be known to be true a priori because their denial would involve a

contradiction and they are thus necessary. Examples are truths in

mathematics and logic. They are intuitively or deductively certain. The

examination of the meaning of the constituent ideas of the propositions

alone is sufficient to establish their truth or falsity. All propositions of

type (II) concern connections between matters of fact and the actual

existence of things, and can be known to be true, if at all, only a posteriori

146 Empiricism

by experience, and not through examining the meaning of the constituent

ideas alone because their denial does not involve a contradiction and

they are thus contingent. Examples are the propositions of natural

science and common-sense statements of fact. The price of our knowing

propositions of type (I), however, is that they are trivial truths that can

tell us nothing about what is actual and contingent, but only what is

possible (not contradictory), impossible (contradictory) or necessary

(denial is contradictory). Thus we cannot know any truths about the

actual contingent or real world a priori by pure logical reasoning alone; if

we can know truths about the world at all, we must rely on the evidence

of experience. Propositions that do not concern either relations of ideas or

empirical matters of fact are meaningless.

Closely connected with this is the way Hume shows that we lack

reasons for our fundamental beliefs by showing that the only two

possible sources of rational justification do not provide reasons for

those fundamental beliefs.

(I’) Reason

Justification by intuitive, demonstrative, deductive or logical a

priori reasoning.

(II’) Senses

Justification by the evidence of observation or a posteriori

experience.

These are exhaustive of the sources of rational justification. Hume

purports to show that rational justification from either source,

demonstrative reasoning or experience, is lacking for our fundamental

beliefs in causation in the world and inductive inference, in the

existence of physical objects in the external world, and in a persistent

self; thus they cannot be rationally justified at all; nevertheless, the

mechanics of the mind are such that we hold irresistibly these beliefs so

necessary for our survival. Hume’s positive contribution is to give an

account of why, in fact, given that rational justification cannot account

for it, we do hold these basic beliefs.

Why, in particular, do we form beliefs about matters of fact that we

have not observed on the basis of what we have observed?

Characteristically this takes the form of an inductive inference of the form:

But is there any rational justification for this inference? Take, for

example, the propositions “All unsupported bodies fall”, “The sun will

rise tomorrow”, or the propositions “All A is B” and “If A occurs, then

B must occur”. These are characteristic of the propositions of natural

Hume 147

science and common sense. Is there any rational justification for our

assertion of these propositions? As it stands the above inductive

inference, which might be used to support such propositions, is clearly

deductively invalid: it is possible for the premise to be true but the

conclusion false. In all such instances we move from cases we have

observed to cases we have not observed on the supposed basis of there

being a causal relation. That is, A is the cause of B, which supposes that

A occurring is necessarily connected with B occurring.

If the inference from A we have observed to B we have not

observed, and the belief that they are necessarily connected, is to be

rationally justifiable, it must be because of (I’) reason or (II’) the senses.

Hume thinks both fail to provide such rational justification.

Hume is clear that the causal connection between A and B, which

describe events in the world, is not explained and rationally justified

by (I’): its being logical or deductive. The relation between event A and

event B is not like the relation in a deductive argument between

premises and conclusions. If the connection were deductive, and hence

logically necessary, then the assertion of A and the denial of B would

involve a contradiction. But in the case of connections of events or

matters of fact this seems never to be the case; the assertion of a

matter-of-fact connection and its denial seem equally conceivable. The

logical relation which holds between a plane figure being three-sided

and its being triangular, or its internal angles being equal to 180

degrees, is the kind of relation that would, if it applied, make a

connection necessary and enable us to justify rationally the inference

to cases we have not observed from cases we have observed; but such

a relation does not hold between events in the world corresponding to

our ideas of them A and B. A and B can exist at separate times,

therefore A and B are separable in thought; the existence of A can be

supposed without supposing the existence of B, and the assertion that

A is always found with B is therefore a contingent, not a necessary,

truth. In short, if it is ever the case that A and B can exist at different

times, we can conceive of A and B as separate, and any connection

between them cannot be necessary.

It might seem as though the causal relation is deductive, and thus

we can know a priori the connection between A and its causal

consequences B because we know the kind of thing A is: say a billiard

ball. But the question arises as to how we know what kind of thing A

is. Hume argues that in the case where A is something entirely new to

us, we can know that B, or anything else, will follow only by experience.

Logically speaking, apart from what would be logically contradictory

anything could happen. If it seems as though we can deduce B from A,

this is because we have already observed the behaviour of A-like

things and included in the definition identifying A as A (what is an A)

the relation to B. We cannot from examining A-in-itself or alone prior

to any experience of A, before a characterizing definition of it that may

148 Empiricism

include B as a causal consequence, deduce what will follow. In

identifying A as an A—as something of a certain sort—we already have

to include certain potential causal consequences; we cannot separate

what we mean by an A—what A is—from all its causal consequences.

To show that we could by pure reason alone deduce B from A, and yet

by this produce new non-trivial knowledge, we would have to define

A independently of its causal consequences, but this is impossible if

what we mean by an A—and hence use to identify something as an A

in the first place—must include the range of A’s causal effects. That

certain causal consequences are connected with A is not something

that can be known a priori.

Alternatively it might be the case that we make the inference from A

to B, and are rationally justified in doing so in accordance with (II’),

because we observe in experience a necessary connection between A

and B when observing the conjunction of an instance of A and B, or B

following A; but in fact we observe no such necessary connection

between A and B, but simply observe A and B occurring together. The

hammer is thrown, hits the window, and then the window breaks;

there is no necessary connection observed as part of this, but rather a

sequence of logically distinct events. We observe no necessary

connection between observed matters of fact themselves, but only

events conjoined with or following one another. Nevertheless, we still

believe some events and ideas to be necessarily connected, and it

remains to be explained why we do so.

Partly the formation of beliefs about the unobserved on the basis of

the observed is founded on the principle that “Every event has a

cause”. But Hume shows that this principle lacks rational justification

by showing that it cannot be justified either by (I’) or by (II’); this

applies Hume’s fork. First, it is not a necessary logical truth, since its

negation does not imply a contradiction; the assertion of an uncaused

event is conceivable. He notes that the assertion of an uncaused event

does not involve the contradictory assertion that the uncaused event is

caused by “nothing”, rather it asserts that the event has no cause at all.

Second, it is not a truth that can be known empirically, since it can be

neither established nor refuted by experience; logically there is no

hope of examining all cases. It cannot be confirmed because we cannot

examine all cases to show every case has a cause; it cannot be refuted

because in any given case we cannot examine and exclude everything

that might be a cause.

If the causal relation between A and B is not deductive, then the

move from the observed to the unobserved on the basis of observed As

and Bs is an inductive inference, and if the assertion of general

propositions such as “All A is B”, or “If A occurs, then B must occur”,

is to be rationally justified, then they depend on some kind of

“uniformity of nature principle”: that conjoined events that we have

observed will hold in cases we have not observed. Thus, events that

Hume 149

we have observed to be constantly conjoined in the past will continue

to be so in the future. In short, the uniformity principle asserts that the

laws of nature will hold in cases we have not observed, and the future

will resemble the past. The acceptance of the uniformity principle

would make the inference, from cases we have observed to those we

have not, rationally justified—the inference would be valid—by acting

as a required premise in the inference from instances we have

observed to those we have not observed.

But what is the rational justification for the truth of the uniformity

principle itself? Again Hume’s fork is applied, this time in testing the

uniformity principle. First, if the uniformity principle were a logical

truth, then its negation would be a contradiction, its denial

inconceivable; this is clearly not the case; it is certainly conceivable that

any law which has operated in all cases until now should cease to

operate in the future and should fail to operate in cases we have not

observed. The uniformity principle cannot be known a priori. Secondly,

the uniformity principle, if it is itself merely a further matter of fact,

cannot be justified by experience for any such attempt will be

irredeemably circular. We might try to justify the uniformity principle

by experience a posteriori by saying: the uniformity principle itself has

always operated or held in the past, and so it will continue to operate

or hold in the future, therefore the uniformity principle is justified by

experience. In applying this to the uniformity principle itself such a

justifying inference is circular, since it is exactly the kind of inference

which depends for its validity on accepting the uniformity principle:

that past observations are evidence that the future will operate in the

same way.

The startling conclusion that Hume draws from his analysis of our

belief in unobserved matters of fact is that such beliefs lack all rational

justification, and thus having a rational justification is not responsible

for our making the inference from observed A to unobserved B

following the observation of A and B conjoined in the past. We do not

make the inference from A which we observe to B which we do not

observe because we are rationally justified in doing so. Nevertheless

we do make the inference, so there must be some other explanation for

why we make it.

Hume gives on the one hand an account of causation and what is

involved in the idea that events are causally connected, on which all

150 Empiricism

moves to unobserved matters of fact depend; and on the other hand an

account of the conditions under which we hold the belief that events

are causally connected.

C’ (a) spatial and temporal contiguity

(b) temporal priority: cause comes before effect

(c) necessary connection between cause and effect

C’’ (a) observed spatial and temporal contiguity

(b) observed temporal priority: cause comes before effect

(c) observed repeated constant conjunction.

The reason for these accounts is that Hume wishes to argue that C’

describes the necessary and sufficient conditions for events being

causally linked and what is involved in the idea that they are, but we

come to hold the belief that they are causally connected in just those

conditions or circumstances described in C’’, and those conditions or

circumstances do not rationally justify the belief as true, nor is there

any other way of doing so.

When we believe A and B in sense C’ to be causally connected:

(1) We make the inference from observed As and Bs to unobserved

As and Bs.

(2) We believe or expect, not merely think, that B will occur

following a fresh observation of A.

(3) We believe the connection between A and B to be a necessary

connection: that it could not be otherwise.

We do not have any rational justification for the inference involved in

(1), for the relation between A and B is neither logical nor justified by

experience. We have no rational justification for the belief (2), since it

cannot be based on either logic or experience. We do not have any

rational justification for the belief (3), since the relation is not logically

necessary, nor is a necessary connection between instances of events A

and B something we observe in experience of A and B; we observe A

conjoined with B, but we do not, as a feature of our experience of them,

observe any necessary connection.

So (1) our making the inference from A to B, and (2) our belief that B

will follow an observation of A, and (3) our belief that A and B are

necessarily connected are not explained by our being rationally justified

in the inference or the beliefs. Hume’s conclusion is that these are not a

matter of rational justification at all. It still remains to give an

explanation of these matters.

The explanation Hume gives returns us to features of human nature,

the principles of the association of ideas and how we react to certain

experiences. The explanation in all the cases (1), (2) and (3) derives

from habits or customs of the imagination: mental habituation. This

tendency to mental habituation is a propensity of human nature. The

basis of the explanation is that repeated observation of the constant

Hume 151

conjunction of A with B as in C’’ sets up a habit of association in the

mind of A and B, and it is this that leads us to (1) make the inference

from A to B in cases we have not observed, (2) believe that B will occur

having had a fresh impression of A, (3) believe that A and B are

necessarily connected.

Hume gives an account in C’’ of the circumstances or conditions in

which we in fact come to judge that A and B are causally connected,

rather than where we are rationally justified in so doing. The

explanation of our belief in causal connections then derives from the

product of those circumstances and our natural reactions in those

circumstances. Following the repeated observation of the conjunction

of A and B in our experience in accordance with the conditions C’’

there is set up in our minds the habit or custom of associating A and B;

and these are just the circumstances in which we say A and B are

causally connected. Taking points (1), (2) and (3) above in turn, Hume

gives the following accounts.

(1) Making the inference from A to B

It is just a fact about our fundamental psychological constitutions

that in circumstances C’’, following the observed repetition of A

and B in conjunction, we do make the inference from A to B. The

repetition of A and B constantly conjoined in our experience sets

up a habit or custom such that on the observation of A we

compulsively move to the idea that B. Thus we infer the idea of B

from the idea of A in cases we have not observed, but the move is

not a rational move at all, since it is neither deductive nor justified

by experience.

(2) Believing that B will follow A

To understand our expectation or belief that B will follow A on

observing A in conditions C’’, we must understand what a belief is

for Hume. He explains a belief as being just the degree of liveliness

or force of an idea, and not a difference in, or addition to, the

content of an idea; the difference between merely conceiving or

thinking X and believing X is a matter of the force and liveliness

with which the idea of X strikes us. In the case of believing B will

follow A, Hume’s explanation is that there is a transference of force

by a kind of inertia from the fresh impression of A to the idea that

B, which enlivens B, where the habit of associating A and B exists,

and this turns the mere thought of B into a belief or expectation—a

lively or vivid idea—that B. It should be pointed out that

sometimes Hume presents a somewhat different theory of belief,

whereby it is a difference of attitude towards an idea, or the

manner in which an idea is conceived or entertained, which

constitutes believing an idea, and which makes believing

something feel different from an imagined fiction: it is an idea

being more strongly or vividly conceived or entertained that

152 Empiricism

constitutes a belief in an idea, rather than a difference in the

vivacity of the idea itself. It is not clear if these two theories can be

reconciled: in the first theory, belief is a matter of how an object of

thought strikes us, in the second theory it is a matter of how we

take hold of the object of thought.

(3) Believing that A and B are necessarily connected

The inference of B from A is not based on the necessary connection

of A and B; rather, the idea of the necessary connection of A and B,

essential to the belief in a causal relation C’, depends on our in fact

compulsively making the move from the impression or idea of A to

the idea of B following the repeated observation of the conjunction

of A and B as in conditions C’’. We have no impression of a

necessary connection between A and B derived from observing the

conjunction of A and B themselves: we just see A happen, then see

B happen. But if the idea of necessary connection, and hence our

belief in causation between events, is not to be a delusion and

meaningless, there must be some impression from which it derives.

The idea of necessary connection derives from a new impression of

reflection, which in this case is the feeling of determination resulting

from the mental habit of our passing from the idea of A to the idea

B, following previous repeated observation of the constant

conjunction of A and B. The idea of necessary connection does not

correspond to anything in the impressions of A and B themselves,

nor does it arise from the perceived repetition of their conjunction

alone, which would in itself produce no new impression; it

corresponds to a new impression of reflection which is a generated

feeling of determination, as we habitually pass in the mind,

because of an associative propensity of human nature, from the

idea of A to that of B, on having repeatedly had experience of the

conjunction of A and B. The idea of necessary connection, and that

of causality which depends on it, would not have arisen at all,

because there would have been no corresponding impression from

which it could arise, except for the propensity of human nature to

produce a suitable new impression of reflection; no impressions of

A and B would alone be sufficient to give rise to the idea of

necessary connection. There is no circularity involved in this

account: the idea of necessary connection derives from the feeling

of determination, whether there is actually any determination or

not, because we in fact move and have a propensity to move from

A to B, which establishes a habit in our minds, following exposure

to the repeated observation of constant conjunction of A and B.

That the idea of necessary connection derives from an impression

of reflection or feeling in this way has a very important

consequence: that the necessary connection, and therefore causal

connection, that we suppose to exist between events themselves

and our ideas of those events is, in fact, in the mind, not an

Hume 153

objective feature of the world; it is something we project onto the

world owing to habit, not something observed in events in the

world, and it is falsely regarded as an objective feature of the

world or real relation connecting events we observe.

In sum, the belief in causal connections, which includes necessary

connection, depends on our natural movement from one idea to

another, not the other way around.

Hume gives an analogous account of the remaining fundamental

beliefs (mentioned at the beginning of the Hume section): (b) the

existence of the external world: bodies continue to exist independently

of us in the external world and (c) the existence of a permanent self.

The strategy is the same: we have no rational justification for these

beliefs through reason or the senses, but nature through the

imagination has ensured that we have these beliefs, and human nature

gives an account of this non-rational mechanism. We believe that there

are bodies existing continuously and independently of us, and that we

are the same self over time.

Hume begins by saying that it is vain to ask if bodies (external

material objects) exist or not, since we cannot help believing that they

do; the question of interest, therefore, is what accounts for having that

belief. The belief in the external world is constituted by a belief in

objects that exist continuously (when not perceived, for example) and

exist independently of perceivers. Reason cannot justify this belief: not

only is it not the case that most people use rational arguments to come

to this belief, but also it is not possible to give a demonstrative proof

that the external world exists such that a denial would be a logical

contradiction. The senses cannot justify the belief: all that we have, if

we examine our sense-experiences or perceptions carefully, is

impressions which are perishing (non-continuous or interrupted) and

dependent (internal or mental) for their existence and nature on

perceivers. All that we are aware of is perceptions which are perishing

and dependent; we do not perceive any objects distinct from

impressions. So what features of our perceptions lead us to believe, or

produce the belief, that our impressions of sense are of external

material objects which do exist continuously and independently of us?

It is not the force or involuntariness of certain impressions that

accounts for the belief, for these are features of impressions, such as

pains, that we do not suppose exist independently in the external

world. The features of our sense-experience from which the belief

derives are the constancy and coherence of certain series of perceptions

which lead the imagination, operating according to certain propensities

of human nature, to overlook the fleeting and internal nature of

impressions. The series of perceptions can be constant in that there are

resembling collections of perceptions in a series even though there may

be gaps between them, as when I look at the table in my room, go out

154 Empiricism

and come back and look again. The series of perceptions can be

coherent in that although the collections of perceptions in a series

change, they do so in a predictable way, as when I come back to my

room and find the fire has burnt down as expected. First, we resolve

the conflict between the gaps in our perceptions and their constancy by

regarding the gaps as only apparent, with the object of our perceptions

really continuing to exist in the gaps. Second, we explain the coherence

of our perceptions by the supposition that the objects perceived exist

constantly and independently in the gaps when not perceived.

Our belief in continuous and independent objects is one in

something that preserves identity through time; this would strictly

involve perceptions which are invariable and uninterrupted. We have

bundles of perceptions which, although perishable and interrupted,

also exactly resemble each other and thus they exhibit constancy.

Because these bundles exactly resemble each other the human mind

overlooks the gaps and lazily treats them as if they were the same

uninterrupted perception. Thus we come to form the belief in, or lively

idea of, continuous and independently existing objects corresponding

to these bundles of perceptions; the belief or lively idea which fills the

gaps itself derives its liveliness from the resembling impressions either

side of the gaps in our perceptions. In short, we naturally and

habitually confuse a series of interrupted but resembling perceptions

with the alike single continuous perception that would be invariable

and uninterrupted, and thus believe that sensible objects exist as

continuous and independent objects.

The belief in the self, or a personal identity that persists over time,

receives similar treatment. Its existence is indemonstrable by reason.

Through experience when we look into ourselves we do not perceive

anything corresponding to the permanent self, or spiritual substance,

in which perceptions inhere, but only particular fleeting perceptions

themselves. The human mind is really a bundle of distinct perceptions

between which we perceive no real or necessary connection. The

explanation for the belief in the self which we nevertheless have arises

from the natural association of ideas which is a product of the

perceptions themselves with unavoidable wedding or associative

propensities of human nature, giving rise to an impression of reflection

which is a feeling that the ideas are connected; but this association of

ideas and the consequent feeling of connectedness between the ideas

depend on us and our nature, and the connection is not a real

connection between the ideas themselves. It is from this feeling of

connectedness, which is an impression of reflection, that the idea of the

mind being unified in a single self, which is a continuous and

unchanging thing, arises and is ascribed to what are really separate

and variable perceptions; this leads us to mistake what is really a

collection of logically distinct perceptions for something that is

connected in a unity and has identity.

Hume 155

Generally we cannot know if the connections we feel exist between

perceptions are real, for we never perceive necessary connections

existing between them, but merely perceive one following another. In

fact, we know perceptions to be distinct existences or atomic; they are

able to exist independently of each other without logical contradiction.

The idea of connection between them is just a copy of a parent

impression of reflection—the sentiment or feeling of determination in

the mind as we naturally associate ideas—but we can have no

knowledge of whether the connection actually holds.

Nature has taken care that we hold our most fundamental beliefs.

We irresistibly believe in causation and inductive inference, and

believe in the existence of independent continuous external bodies and

a persistent self, even though we have no rational justification for the

beliefs from reason or experience. Thus nature ensures that the

arguments of the sceptic find no purchase against processes that are

not a matter of rational justification at all but are a matter of deep

instincts in human nature.

156 Empiricism

continued to ...

https://sites.google.com/site/philosophygreekancient/philosophy-and-philosophers---an-introduction-to-western-philosophy---chapter-4-1