In the March 10 edition of the BBC Radio 4 program In Our Time, the three guests discussed the subject of free will. Does it exist? Could it exist in the age of science? Or is it just a mistaken notion that is a hangover from religion, related to what is needed in order for people to be responsible for their own actions, and hence where they end up in Eternity?
This discussion was by philosophers, not neuroscientists, but the neuroscience and general-science perspective is there. The discussion is quite interesting. The idea of free will arises because we so much feel that we have it, that we make decisions.
The issue for us relates to the concept of determinism. If the universe is completely Newtonian, that is, follows perfect laws at all scales of observation, then everything is related to and in that sense predictable by anything. At the time of the Big Bang, what you are going to have for dinner was, in principle, predictable. That would have fundamental consequences for evolution, since in a purely deterministic universe there is no real competitive factor among rabbits and foxes: the slowest rabbit was fore-ordained to be dinner for the fast fox. Random variation screened by unpredictable experience is not what's going on, despite the Modern Synthesis claims to the contrary!
Of course this is all nonsense, because to see that everything is predictable you probably would have to be outside the universe to observe it, but the idea of a totally deterministic universe is that it's entirely of itself--no outside agent that could meddle, or even observe it.
Anyway, if this is the world we're in, then nobody is responsible for their actions in the moral sense, not even Stalin or Hitler or Ghaddafi, or Mother Theresa for that matter. We are determined from conception by our genes, and our environment. Our neurons wire up during life, in totally predictable ways (predictable in principle, that is, if one knew where every molecule and every neural cell was at every instant, etc.), and so the thoughts we think are just the result of that wiring--not in any sense freely thought by us, if thoughts really are just signals flying around among neurons.
As the discussion in the BBC program points out, even if randomness exists, we aren't morally at free will, because we're the combination of pure physical determinism, plus chance events that we don't control. Thus the usual appeal to quantum mechanics probability doesn't change the story of determinism vs moral responsibility.
But are even 'random' events like mutation really random? If they are not, but are just determined in ways we can't understand, the world returns to deterministic laws-of-Nature status.
But what is a 'chance' event? Is it one with no cause? Or is there some kind of cause that is probabilistic--clearly something we do not understand? If, for example, random mutations really follow some laws of probability, then determinism just takes a slightly different form. Free will remains in the realm of the non-material, and hence mystic and non-existent illusion.
So, if our thousands of genes controlling the behavior of billions of cells, in environments with many chance factors, are just working out the physical forces, there is no such thing as free will, no matter how it feels to us. If there is true probability (neurons wire to some extent just by chance, truly), then there may indeed be something that would genuinely approach free will: it would not be predictable, even by probability distributions (because the latter would not be pure chance, but a different kind of cause). In terms we understand, at least, pure chance is an effect without a cause!
More likely, what we're learning by all our omics technologies is essentially that things appear so random, and there is so much of it, that we can never, even in principle collect enough data to predict whether you'll have this or that flavor ice cream today, or whether you'll have chicken or pasta on your next overseas flight. Even if the appearance of randomness in brains, like that in tossed coins, is really just an illusion of randomness.
It is thus hard to escape that no matter how it looks, all that seems to be free will is illusion, not true free will. And it's dispiriting to feel that so much of life is an illusion (a view that Darwin is supposed to have expressed, though we don't remember seeing the quote - if you know it, let us know). But if free will is an illusion, mistaken appearance of causeless effects, then for the very same reasons, so is natural selection. And that is food for thought, for people as well as the happy, not really just lucky, fox.