Do we truly have free will or is it merely an illusion? Clearly, if we cannot exercise free will at all, our world immediately becomes amoral. If no choice is possible, how can there be credit or blame attached to good or bad acts? And where's the fun in a world where we can't pass judgement on our fellow travellers? So, we'd better make house-room for free will if at all possible, and to do so, we'd better be ready with counter arguments for the nay-sayers.
Deniers of free will are from two main camps, one religious and one secular. The religious argument comes in many flavours, from Krisna to Calvin, but boils down to Predestination: everything is preordained by God. The secular version, Determinism, is almost an impersonal version of the same: everything is governed by initial conditions and the laws of Physics.
There is also a hybrid version which could read: God created the initial conditions and natural laws, knowing exactly what was going to happen, then went for a beer. It's easy to see how this version evolved. Over the years, Science has produced better and better explanations of phenomena that had previously been the province of religion. The religions, unable to deny scientific advances but unwilling to yield ground, came up with the 'God as Scientist' notion: He didn't say 'Let there be light' after all; He said 'Let F=GMm/r² and let E=mc²', threw in a handful of stardust and let Physics get to work. You could say this is Predestination by Determinism.
Personally, I see no evidence for God's existence, which leaves no room in my philosophy for Predestination. However I acknowledge that there is no logical way to disprove it, just as there is no way to disprove the existence of God.
Determinism is a different animal. It's undeniable that the Universe is at least partly deterministic. Apples fall. Cork floats. Comets return on cue. Babies are born. But Determinism isn't absolute, even in the physical world. Chaos theory applies to complex macro systems and at the quantum level the Uncertainty Principle is well established. Whether or not you believe in a created Universe, there is no denying that it contains a liberal helping of randomness.
So, whether you believe that free will is a gift from God or just another manifestation of consciousness, it seems reasonable to assume that it too will be subject to a degree of 'fuzzy' determinism. (Fuzzy meaning with an element of randomness). This is very easily illustrated by experiment, as I hope to demonstrate:
The fact that you've been reading this for the last few minutes tells me that you are breathing. But until I drew your attention to that fact, you probably hadn't given it a second thought. You've been breathing until now, not by will, but by instinct. But now, you are conscious of your breathing. You can, by an exercise of free will, breathe in, right now, to a count of five. And out again. One, two, three, four, five. Easy. Free will - you are willingly playing a breathing game that I have suggested you play. What you cannot do, now, is instantly revert to unconscious breathing. Try... See what I mean? Something similar happens if someone orders you not to think of elephants for the next two minutes. But don't worry. The self-consciousness will disappear when you are distracted, and the breathing will revert to instinctive mode.
We seem to have shown that even in such a simple activity as breathing, we can opt in and out of free will mode. However the act of opting in or out is not necessarily in itself an act of free will. It can be triggered by external forces, such as someone making suggestions. Just toying with ideas here, but free will seems to be in some way correlated with self consciousness. And that might make sense too, because experience tells us that free will, or character, is more in evidence in the more sentient species. C.S. Lewis wrote, "A cow cannot be very good or very bad; a dog can be both better and worse; a child better and worse still; an ordinary man, still more so; a man of genius, still more so; a superhuman spirit best- or worst- of all". Though the jury is still out on superhuman spirits, the message is clear: Free will correlates with sentience.
So far, so good. But are there limits to our free will? You bet there are. Remember, we're in a partially deterministic Universe. I'm pretty sure you can hold your breath for twenty seconds, as an act of will. Thirty or forty maybe, if you're quite fit and healthy. But ninety seconds under water? Your physiological need for oxygen will rip straight through your will power and you'd better surface fast because if you don't you're going to suck in a lungful of water - against your will.
So where is all this leading? Only to this: Free will is manifest where self-consciousness triumphs over instinct by creating the necessary conditions for its own continuation. We are truly alive to the extent that we take control of our lives, by thinking and acting in the best interests of our own minds.