The relationship between determinism and science is fairly obvious. Scientists do not explain events in terms of free will; rather they seek causal explanations. As scientific knowledge has increased, more and more events have become explainable through cause-effect relationships. With respect to human actions, scientific knowledge about genetic characteristics, the biochemistry and physiology of the human body, and the effects of environmental conditions all contribute to greater recognition of these relationships. Noting this trend of increasing causal explanation with scientific progress, determinists extrapolate to the conclusion that all human actions are determined and that belief in the traditional conception of free will is based upon incomplete scientific knowledge. We cannot conclude that all scientists are determinists; but we can observe that no scientist maintains scientific respectability in a field by simply attributing the occurrence of events to free will. For example, a political scientist analyzing an election will not get far trying to publish an article that explains results simply by attributing votes to acts of free will.
Within the deterministic position, we can distinguish two interpretations based upon whether the causal processes occur within a closed or open system. In a closed system, every event―past, present, or future―is completely predictable, in principle at least. In the words of Pierre Simon LaPlace (1749 - 1827 C.E.), a mathematician and astronomer,
We ought to regard the present state of the universe as the effect of its antecedent state, and as the cause of the state that is to follow. An intelligence knowing all the forces acting in nature at a given instant, as well as the momentary positions of all things in the universe, would be able to comprehend in one single formula the motions of the largest bodies as well as of the lightest atoms in the world, provided that its intellect were sufficiently powerful to subject all data to analysis; to it nothing would be uncertain, the future as well as the past would be present to its eyes.1
Note how LaPlace's determinism is extremely mechanistic―everything in the universe is ultimately explainable and predictable in terms of the motions of physical bodies, governed by physical laws, ("the forces acting in nature"). Here is another frequent characteristic of causal interaction in a closed system: it is conceived to be reductionistic. In other words, the objects and events of everyday or gross experience can be explained through a reduction process whereby they become the effects of causal interactions among the elements composing them. With respect to human actions, this view might entail the following sort of reduction: social phenomena are explainable in terms of psychological phenomena, psychological phenomena are explainable in terms of biological phenomena, biological phenomena are explainable in terms of physical phenomena. Not only is there no free will, but also, all human actions are entirely explainable as the effect of the motions of bodies as governed by the laws of physics. Thus human actions would be explainable through non-human, or subhuman, causal interactions.
Causal interaction in an open system offers an alternative interpretation of determinism. The interpretation is based upon the principle that a whole can be greater than the sum of its parts or, put differently, that an organized totality is not entirely predictable or explainable through the elements composing it. Causal interaction in an open system is organismic. With respect to human actions, this means that they are determined but still not reducible to explanation in terms of the non-human or subhuman elements composing them. According to this interpretation, the sciences of physics, chemistry, biochemistry, and physiology are all relevant and necessary for explanation of human actions; but they are not sufficient for complete explanation. Causal interaction in an open system allows for reasons and intentions, consciously conceived, to be essential in explaining what human beings do. It also allows for the possibility of unpredictable novelties. That is to say, in so far as the whole can be greater than the sum of its parts, it follows that, regardless of the state of our intelligence or information, we cannot always predict completely (even in principle) the properties and activities of an organized totality that will come into existence in the near or distant future.
If this open system interpretation of determinism is still hard to grasp, perhaps the following two examples will help. According to causal interaction in an open system, no one (no matter how intelligent or knowledgeable) could have predicted the evolutionary development culminating in the human species with exactitude four billion years ago. Also, no amount of information about the properties of hydrogen and oxygen separately could make possible a prediction of all the properties of water. For example, a prediction about the taste of water would be impossible.
When most people discuss scientific determinism, they usually are talking about causal interaction in a closed system. In so far as this interpretation is reductionistic, it makes very difficult the attribution of moral responsibility to human beings because what they do is ultimately governed by the laws of motion for physical bodies, a governance quite alien to the whole realm of morality. Indeed, the issue of moral responsibility provides the basis for one of the strongest objections to scientific determinism. Some advocates of causal interaction, so-called hard determinists, are willing to deny the existence of moral responsibility entirely; others, so-called soft determinists, usually preserve moral responsibility by reinterpreting free will so that it becomes compatible with determinism.
Some Objections and Possible Replies
(Note About Objections and Possible Replies: You should look upon the objections and possible replies as opportunities for further thought rather than as definitive statements. Holders of the original position are not likely to be overwhelmed by the objections; and critics of the original position are not likely to be convinced by the possible replies. These objections and possible replies accomplish a proper goal if they push you to think more deeply about an issue, leading you to seek more clarity and justification in drawing your own conclusions.)
If all our actions are determined and there is nothing we can do to change events, then we might as well sit back and let events happen. For example, if we believe in determinism, this just means that we were determined to believe that way; and if we believe in free will, this just means that we were determined to believe that way. Thus there is not even any point to seeking truth, since we only accept what we are determined to believe, anyway.
A Possible Reply: The deterministic conditions that affect us do not lead to our sitting back and letting events happen. Moreover, acceptance of determinism in no way makes such fatalism a plausible alternative. We are well aware that what human beings do, regardless of the origin of the actions, does change the course of events. For example, the actions of Plato, William Shakespeare, Queen Elizabeth I, Isaac Newton, Napoleon, Abraham Lincoln, and Martin Luther King, Jr.―even if determined―changed the course of human events. So long as we do not know all the deterministic conditions affecting us, we can never conclude that we should "sit back and let events happen."
As for the possibility of truth, there is no special problem with determinism. As time goes on, we expect to become increasingly aware of the conditions operating throughout the universe. If mistaken beliefs arise, then we can hope that the subsequent course of events will produce conditions that change the belief. Errors are quite commonly corrected in this fashion.
(2) Necessary, But Not Sufficient, Conditions
In making their arguments, what determinists always point to are necessary, but not sufficient, conditions for human actions. For human beings to be what they are and act, a great variety of conditions are necessary. Everyone must have a genetic endowment, functioning physiological processes, and influencing environmental conditions. We should not make the mistake however of concluding that these necessary conditions are wholly sufficient to explain human actions. All these necessary conditions can be present, while free will is still a factor in human actions.
If determinists could fully predict all that human beings do on the basis of knowledge of pre-existing deterministic conditions, then they could claim complete explanation of human actions without reference to free will. But they cannot make such predictions now or in the foreseeable future. Hence we are justified in concluding that their arguments rest upon necessary, but not sufficient, conditions for human actions.
A Possible Reply: Complete prediction is not possible because we cannot know all the deterministic conditions affecting human beings in all the situations of life. What is significant however is (1) the increased predictability that has accompanied increased scientific knowledge, and (2) the decreased reliance upon free will to explain human actions. Actions once attributed to free will may now be explained through socio-economic conditions or perhaps a neuro-physiological state. For example, we now have scientific evidence that severe protein deficiency in early childhood permanently impairs intelligent decision-making ability in later life. Given the increased predictability that has accompanied increased scientific knowledge in the past, we can safely extrapolate to the conclusion that all human actions are determined. The distinction in the objection between necessary and sufficient conditions says something about the current state of knowledge; but it does not establish the absence of determinism.
(3) Contra Reductionistic Causal Interaction
By explaining actions through non-human or subhuman conditions, reductionistic causal interaction deprives human actions of any human significance. More particularly, it eliminates the whole realm of morality, since morality has nothing to do with any ultimate explanation in terms of laws of physics accounting for the motions of bodies. Now since we cannot eliminate morality from human life, there must be something wrong with reductionistic causal interaction.
A Possible Reply: Reductionistic causal interaction will not eliminate morality, because people always continue to have moral feelings. It may eliminate some useless ethical disputes and some mistaken tendencies to apply moral praise or blame; but our lives will not lose their human significance.
(4) Transcending Environmental Conditions
How do we explain how a person transcends environmental conditions, if we are determinists? We have all heard about instances where a person grows up in the midst of poverty, squalor, violence, hopelessness, purposelessness, and depravity but then goes on to become a ballet star or a novelist or a biochemist. Free will offers a sounder explanation of such instances than determinism does.
A Possible Reply: Just because some individuals seemingly transcend their environmental conditions, we should not be blinded to what happens to most people under a set of such conditions. If we look carefully at the specific conditions affecting these relatively rare individuals who seem to "escape," we do not have to give up deterministic explanation. Usually, we find some special condition(s)―for example, great natural endowment, a particularly strong family life, the influence of some person who sparks interest and shows confidence in the individual, or the opportunity offered by some private- or government-sponsored program―present. Hence there is no need to attribute the greater accomplishments of these individuals to free will.
2.4 Would you agree with the claims that (a) there is a close relationship between determinism and science and (b) as science progresses, the explanation of human actions increasingly favor determinism over free will? Does the distinction between causal interaction in closed and open systems seem important to you? Why or why not?
2.41 Consider several of your actions to find out whether they exemplify free will or determinism. Explain your reasoning. If you are unsure, what further information would you want in order to settle the issue? Would it ever be possible to get the information? If not, what do you conclude about free will and determinism?
2.42 Evaluate the various Objections to causal interaction mentioned here. Be sure to consider the Possible Replies, in making your evaluation. Which is the strongest objection? The weakest? Would you offer other objections besides those mentioned? If so, what are they? What is your general evaluation of causal interaction?
1. Quoted in Will and Ariel Durant, The Story of Civilization IX: The Age of Voltaire (New York: Simon & Schuster, 1956), pp. 547-548.
(Note: The 1986 copyright was initially held by University Press of America, Ron Yezzi, Directing Human Actions: Perspectives on Basic Ethical Issues--but was then transferred to me.)
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