Knowledge, certainty and system
In the main, On Certainty charts the context of ordinary knowledge claims and expressions of doubt. Our knowledge claims and our doubts form a system. Without this context they would not have any clear meaning.
All testing, all confirmation and disconfirmation of a hypothesis takes place already within a system. And this system is not a more of less arbitrary and doubtful point of departure for all our arguments: no, it belongs to the essence of what we call an argument. The system is not so much the point of departure, as the element in which arguments have their life. (§105)
Wittgenstein also calls this system a ‘picture of the world’ which members of a community largely share. But we do not as individuals arrive at such a world-picture by satisfying ourselves of its correctness. ‘No: it is the inherited background against which I distinguish between true and false.’ (§94) Thus the suggestion is that in order to test or check a claim just such a background is required to provide the ground-rules for empirical inquiry. Thus the background itself cannot as a whole be checked for its truth.
So the background is not treated as doubtful – it simply is not doubted – and is thus held certain whilst knowledge and doubt are symmetric.
Five other features of this background are important
1: It comprises a motley of different sorts of ‘claims’. Moore’s example that ‘this!’ is a hand is one. Others include the claim that the earth existed long before my birth; that my name is such and such; that I have never been to the Moon. So if these claims are taken to express a kind of foundation for empirical inquiry, it is not a traditional view of foundations within philosophy. Traditionally, these have been construed as an homogenous class of claims about my own mental states, experiences, or appearings in my visual field.
2: There is some difficulty in characterising our epistemic attitudes to the ‘claims’ which comprise the background. They are typically not claims we make. Contra Moore we do not know that ‘this is a hand’ because it not the sort of thing we could doubt or provide grounds for. Neither are they beliefs or assumptions. Rather they are certainties expressed by our actions. Thus for example, we do not assume that we have feet when we stand up, but our animal certainty here is expressed in our lack of tentativeness in standing. ‘In the beginning was the deed’ (§402).
3: As the point above suggests, Wittgenstein separates the concepts of knowledge (and doubt etc) from that of certainty. He argues that there is symmetry between knowledge and doubt. We can only claim to know what it would also make sense to doubt. This is because both belong to a ‘language-game’ or linguistic practice of asking for and giving reasons. Certainty, by contrast, characterises the necessary background for that practice. It is the mark of what lies at the edge of empirical inquiry and is not called into question. Certainties ‘lie apart from the route travelled by enquiry’ (§88).
4: Just as the background comprises a motley of different sorts of matters which are taken as certainties, so too the limits of reasonable empirical inquiry are taught by example. This is another case where the rationality comprising empirical inquiry resists codification as a theory. We do not have a theory about what can and cannot be doubted. ‘We do not learn the practice of making empirical judgements by learning rules. We are taught judgements and their connexion with other judgements. A totality of judgements is made plausible to us.’ (§140)
5: Whilst the systematic background or picture of the world is a prerequisite for empirical testing, elements of it can be called into question. ‘The mythology may change back into a state of flux, the river-bed of thoughts may shift. But I distinguish between the movement of the waters on the river bed and the shift of the bed itself; though there is not a sharp division of the one from the other.’ (§97)
Scepticism?
Note that in saying the knowledge is not certain, Wittgenstein does not say that it is not true. That is obvious from the traditional definition (knowledge = justified, true belief) but one can forget it. Knowledge is factive. If Smith knows that p then p or ‘p’ is true. (Likewise seeing is factive. Belief is not. If Smith believes that p, p may well not be the case / ‘p’ not true.)
Certainty would be more that Smith herself could not doubt what she thought she knew. That is quite different from idea that the knowledge itself – if she has it – being true. (Note this view is contentious. John McDowell thinks that knowledge removes doubt though can be mistaken.)
One reading of this account is that Wittgenstein accounts for our everyday account of knowledge – how we use the concept of knowledge – even if he does not address scepticism. To think whether he does successfully address scepticism think about this passage:
The idealist’s question would be something like: “What right have I not to doubt the existence of my hands?” (And to that the answer can’t be: I know that they exist.) But someone who asks such a question is overlooking the fact that a doubt about existence only works in a language-game. Hence, that we should first have to ask: what would such a doubt be like?, and don’t understand this straight off. (§24)
So the main challenge is whether we can understand scepticism. Wittgenstein’s injunction is don’t understand this straight off.
But is it an adequate answer to the scepticism of the idealist, or the assurances of the realist, to say that: “There are physical objects” is nonsense? For them after all it is not nonsense. It would, however, be an answer to say: this assertion, or its opposite, is a misfiring attempt to express what can’t be expressed like that. And that it does misfire can be shown; but that isn’t the end of the matter. We need to realize that what presents itself to us as the first expression of a difficulty, or of its solution, may as yet not be correctly expressed at all. Just as one who has a just censure of a picture to make will often at first offer the censure where it does not belong, and an investigation is needed in order to find the right point of attack for the critic. (§37)
Wittgenstein does not say that this line is easy. Is it enough? This is what Michael Williams says about this paragraph.
Why is it an inadequate answer to the idealist and the realist to say that “There are physical objects” is nonsense? In saying that it is not nonsense “to them”, Wittgenstein is not saying that it is not nonsense. Nor is he conceding that the idealist and realist have given it a sense: not a clear sense, anyway. The point is rather that these philosophers— all of us when we are in the grip of sceptical anxieties--will not recognise that it is nonsense. They (or we) think that “There are physical objects” can be understood as an empirical hypothesis. They (we) suffer from an illusion of meaning, the source of which remains to be exposed.
The realist wants to say something correct: that there is nothing defective in the confident way we talk about tables and chairs and rocks and trees. But one cannot make this point by insisting that, contrary to the sceptic or idealist, there really are physical objects out there, as one might insist that there really are mountains on the Moon. (They are not just a trick of the light). The realist’s way of asserting the legitimacy of everyday talk about physical objects misfires: it uses logical vocabulary to make what is intended to be an empirical claim about the world beyond language. This much, Wittgenstein thinks, has been shown. But this is not the end of the matter because the confusion that has been identified is not gratuitous, not the result of mere blindness to the contours of the conceptual landscape. Rather, our confusion is induced by ideas that have yet to come into view. Until we have identified these ideas, we will not have found the right point of attack. [Williams, M. (2004) ‘Wittgenstein’s refutation of idealism’ in McManus, D. (ed.), Wittgenstein and Scepticism. London: Routledge]