I have advanced an argument here for the notion that our consciousness is necessarily causally efficacious. I want to talk on this occasion about free will and more specifically to address a common conception of what it means to have free will -- namely the notion that in any given situation one could have behaved differently from how one actually did behave.
American professor of biology Jerry A. Coyne has written:
I mean it [free will] simply as the way most people think of it: When faced with two or more alternatives, it's your ability to freely and consciously choose one, either on the spot or after some deliberation. A practical test of free will would be this: If you were put in the same position twice — if the tape of your life could be rewound to the exact moment when you made a decision, with every circumstance leading up to that moment the same and all the molecules in the universe aligned in the same way — you could have chosen differently.
In my experience this definition that stipulates one has free will if one could have chosen otherwise is a very common one. Unfortunately it is often left unstated as to the precise meaning of this -- as if its meaning were entirely unambiguous. The problem here is how the precise meaning of "could have" is to be construed. Does "could have" mean that I have the capacity to behave in a given way, even though inevitably I will not? This would be my own position. Or does it mean that given the precise same circumstances and the precise same physical configuration of the Universe, I need not inevitably make the same choice every time? That is to say if we keep rerunning the tape of my life a sufficiently large number of times up to the choice in question, then I will eventually make a different choice? Expressing it as Jerry Coyne does in terms of the tape of ones life, strongly suggests to me that he means the latter. From my reading around on the subject of free will I also get the impression that there are other philosophers and scientists who share this conception. Unfortunately this interpretation seems to me to be unintelligible.
Suppose I were to spot a £20 note while I was walking around outside. I would stoop down, pick it up, and put it into my pocket. What if we were to keep replaying the tape of my life an arbitrary large number of times? Would my behaviour ever differ at this point? I can't imagine it would do. Why would it?
Let's consider another scenario. Imagine you could travel backwards in time to some famous historical event. Imagine also that you don't reveal your presence to anyone and you have no impact whatsoever on the environment. In this case these historical figures will say and behave as the history books tell us. We will know their future lives in their entirety. And however many times we revisit a specific time and place, these historical figures will say and behave precisely as they did on all previous occasions.
This also implies that if someone from the future were to covertly observe us, and if we make a mark so that our actions are recorded in the history books of the future, then that time traveller might in principle know precisely what we will do and say at a specific time and place. And again, should our time traveller keep revisiting that specific time and place, he will not see any variation in anything that we do and say.
Now I would submit that it would be absurd to conclude that these scenarios demonstrate we do not have free will. In the £20 note scenario I would pick it up because of the obvious reason I can purchase goods and services with it. If we rerun the Universe numerous times why would I ever choose differently? Similar reasoning applies to our time travelling thought experiment. If we travel backwards in time, and we do not even disturb the motions of any molecules, then this scenario differs not at all to the one whereby we stay in the present, but we are able -- via some future technology -- to visually view past events "as they happen". Or if aliens on some exoplanet 100 light years away -- presently viewing the earth via a colossally powerful telescope -- are currently watching events unfold on the earth as they happened 100 years ago. Clearly the events they view would not differ in any way from what we know took place 100 years ago.
So it seems to me that the words "could have" certainly ought not to mean that if I reran the Universe I might have acted differently. When I exercise my free will I deliberately choose a particular course of action. Even where my choice is simply arbitrary, for example I really do not care whether I go right or left when I'm out on a walk, that same slight disposition to turn left will still exist if we reran the Universe.
But it seems to me that Jerry Coyne -- and many other scientists and philosophers who have defined free will in the same way -- do have this meaning of "could have" in mind. But then what they're doing is advancing an unintelligible conception of free will.
At this point Jerry Coyne and others of a likewise opinion might agree with me that such a conception of free will is indeed unintelligible. But they might argue there are no other conceptions of free will which can be rendered intelligible. The arguments I have advanced merely serve to illustrate that human behaviour is as determined as any other physical process or change in the Universe. Hence our future behaviour is as fixed as, for example, the motion of the Earth as it orbits the Sun, or the motion of a boulder as it rolls down a hill.
I think though that such reasoning would be wrong. The mere predictability of someone's behaviour is not typically thought to conflict with commonsensical notions of free will. The more we get to know a friend, the more we will be able to predict his behaviour or the views he will express. However it would be absurd to suggest that this makes him less free, or that he never had any free will in the first place.
What we need to understand is that the predictability that your friend will pick up a £20 note if he spots one on the ground, and the predictability of the path of the Earth as it orbits the Sun, seem to have quite distinct different causes. We regard the behaviour of your friend as being caused by a specific intention in his mind and an end goal -- it is this conscious intent which initiates his behaviour.
But the behaviour of the earth? Well I submit that most of us won't regard that the Earth orbits the Sun because of a conscious intent on the Earth's part, or because it wants to! Typically we regard the Earth as being constrained to follow the path it does. That is it does so either because physical laws govern the Universe or because gravitation represents some force or warping of space-time which compels the Earth to follow the path it does. If the Earth were to suddenly stop in its path, or to orbit the other way, or to jig up and down, this would be considered miraculous, and indeed deeply worrying! This is in stark contrast to the case where I ignore the £20 note on the ground and simply walked on by. The latter would be irrational and it would never happen. But the impossibility of it happening seems to be of a wholly differing nature to the impossibility of the Earth suddenly stopping in it's path round the Sun and jigging up and down. Certainly my failure to pick up the £20 note would not be considered miraculous!
The important thing to bear in mind is that, in contrast to other physical objects, we are not obliged to conclude that a person's voluntary behaviour is wholly caused by physical laws or other external factors. Given a particular physical state of the Universe, it need not be physical laws coupled with this physical state that wholly determines what we normally take to be our voluntary behaviour. Rather one's voluntary behaviour is caused by the self or consciousness, and this choice will inevitably be a specific unique one given a particular physical state of the Universe. This also might suggest that a specific unique future exists -- not because we are hapless puppets controlled by physical laws -- but because we do not act randomly but make specific choices in a given situation. However, as I hope I have made clear, this is entirely consistent with a full-blooded commonsensical conception of free will.
I hasten to add though that I have not shown that such a full-blooded commonsensical conception of free will exists. The majority of scientists and philosophers will deny that the origin of our behaviour differs in kind from the rest of the Universe. They are liable to express the view that if physical laws govern the path of the Earth as it orbits the Sun, so too do physical laws govern our behaviour, it's just that we are vastly more complex so it is not so readily apparent that they do so.