Determinism

For about a century, this question has been tied up with what is now called neuroscience—the science of the brain and the central nervous system. If nobody or hardly anybody really believes conscious deciding and so on is just neural activity and nothing else, almost everybody who looks into the question thinks there is a close connection between brains and minds, between neural activity and conscious or mental activity.

Neuroscience has been much concerned to relate particular kinds of conscious events to particular kinds of neural events. It assigns kinds of conscious events to certain locales of the brain, if not in the simple way of early neurophysiologists. But the main point is that neuroscience has taken the brain to be subject to causation. It has taken neural events to be effects. That is, it has assumed that the most general idea of determinism, the one with which this discussion started, is true of all the events in the brain. It still does, despite thoughts brought to bear on it by a few enthusiasts for the interpretation of quantum theory also mentioned at the start.

The argument that comes out of this, in short, is that if the brain is just effects, and the mind is closely connected with the brain, intimately bound up with it, then the mind has to be just effects too. If all neural events have to happen as they do, without any other possibility, then the same is true of the conscious events that go with them—different events but events that cannot possibly be separated from the brain events. If the brain is a machine, then what is bound up with it must also be a sequence of cause and effect.

The argument going the other way is about all of reality, not just brains, and it is owed to taking physics as somehow the fundamental science. In particular it is owed to the interpretation of quantum theory mentioned already. Reality is divided into two levels, the very small particles and the like of what can be called the microworld, and then the larger things in the macroworld, say from ordinary neural events that go with decisions and the like up to explosions and tides. The main proposition is that in the microworld there are events—they really are events—that are not effects.

Therefore they are chance or random events. That is not to say that one is unable to find the explanations of why they finally happen—as distinct from finding out that they are probable or what makes them probable. To say an event is a real chance or random event is to say there is no explanation in reality of why it finally happens. God, if he tried to explain this, could not, since there is no explanation to be found. There is no such thing in the world.

The present author does not go along with this argument. One reason is that although quantum theory is very useful indeed, the interpretation of it has never been proved in the ordinary sense of the word.

A second reason has to do with the two worlds and in particular with the two worlds in so far as they have brains in them. Conscious events like decisions, as one knows, are bound up with macroworld events in the brain, the ordinary events studied in neuroscience. And to add something left implicit so far, these larger events are of course related to or somehow consist in small microworld events in the brain.

The next thing to be said is that the ordinary events investigated by neuroscientists are like all the rest of the events in the macroworld: they certainly do not seem to be and certainly are not taken to be chance or random events. Whether a transmitter substance is released by a neuron, for example, is taken to be a matter of cause and effect. It is definitely not taken as something absolutely without an explanation. This is a reason, as one has heard, for thinking that the related conscious event is also a matter of cause and effect, but that is not the present concern.

How does the ordinary neural event relate to the micro-events down below, microevents that at least enter into the ordinary event? If the microevents are chance or random events, as people ask, does this translate upward into the ordinary events? Does it make the ordinary events indeterministic? For anyone who wants to deny determinism with respect to the ordinary events, there seems to be a certain dilemma here.

Either there is a kind of tight relation between the microevents and the ordinary events or there is not. Either there is translation upward or there is not. Well then, since the ordinary events are plainly a matter of cause and effect, there are two possibilities, both of them bad news for the antideterminist. (1) Since ordinary events are effects and there is translation up from below, then the microevents must also be effects—despite exactly what is said of them. (2) Or given that the ordinary events are effects, it could be that the microevents are not effects but there is no translation upward. But then the fact about microevents not being effects does not matter. It is irrelevant.

But this article has to leave that and come to the main question considered by philosophers. It is not the truth of determinism but the question of what follows if it is true. What are the consequences of determinism—consequences for people's lives, for their freedom and responsibility?