Yes, we have free will. Recent advances in neuroscience suggest some viable explanations for how we can have free will. Google "CEMI field theory" for more info.
Without free will, life is pretty much pointless. Nobody would have any incentive to do anything because whatever happens was destined to happen regardless of what we do. Pretty bleak, don't you think?
Darwin's natural selection tells us that our greatest attribute (intelligence) is necessarily evolved to do what it does: make choices. Human intelligence is NOT predetermined by some causal chain reaction set off by the Big Bang. We are INFLUENCED by causality but not absolutely controlled by it.
In physics, causality rules the INANIMATE physical universe. Until life came along (10 to 12 billion years after the big bang) the universe was entirely inanimate. With life, matter gained motility: the ability to move about WITHOUT outside influence. Motility is one obvious difference between animate and inanimate matter.
Many animals, particularly mammals, appear to possess consciousness -- if not intelligence. Certainly, humans possess both. The introduction of consciousness wrought another milestone in the history of the universe -- and only animals possess it.
I would define intelligence as the ability to anticipate, plan for, and use causality for independent reasons. Human intelligence certainly fits that bill. Human intelligence is the latest milestone in the evolution of life. This milestone came about in just the last 1 or 2 hundred thousand years: a mere drop in the bucket of cosmic time. We are on the cusp of an evolutionary revolution that is accelerating at breakneck speed.
The first phase of universal history -- the Inanimate Phase -- lasted 10 to 12 billion years. The second phase -- the Animate Phase -- has been around for 3.5 billion years. The most recent phase -- the Human Phase -- has only existed for a hundred thousand years or two. The duration of these phases are shrinking exponentially. The next phase might well involve the combination of human intelligence with artificial intelligence. Who knows?
But one thing's for sure: we ALL live, work, play and plan as if we have free will. "Hard" determinists might claim that's an illusion. I claim they can't see the forests for the trees. Yes, causality is an undeniable fact of physical existence. However, its absolute realm is the INANIMATE, physical, universe. For instance, if I hit a billiard ball on the right side, it will veer left every time. If I hit a worm on the right side, it might coil into a writhing knot or wiggle to the right or accelerate forward or whatever. Clearly, ANIMATE BEINGS react to causality differently than INANIMATE THINGS.
Human intelligence is another example of why animate beings can't be treated as if they're the same inanimate stuff as the rest of the universe. If you read the recent neuroscientific literature, you'll find the human brain has many feedback mechanisms performing various functions. There's at least one feedback mechanism that grants us the power of mind over matter (brain). This feedback mechanism is reliably demonstrated by the "bio-feedback machine". With this machine, just a few physiological readouts of subconscious processes allow us to control those processes with a little practice.
Mental feedback is the key to free will. It seems incredible but we are able -- via mental feedback -- to direct the very brain that spawns our consciousness. This is a powerful fact because it allows us to counter the inexorable tide of causality.
My favorite example of this is the 1969 manned mission to the moon. Hard determinists who say that our actions and fate are predetermined by causality, are claiming that all the coordination, cooperation, resources and effort it took to put man on the moon was inevitable and scripted ever since the Big Bang. If you’re a determinist, then you believe all the details involved with putting man on the moon were predetermined billions of years ago. With a script so precise and mystical, you might as well say God wrote it.
Yeah, right . . . “May the the force be with you.”
The "compatibilist" view that free will coexists with causality goes much further than determinism to explain our special role in the universe: including our achievements, failures and limitations.