I've written a lot about free will on this blog. More accurately, my posts on this subject have been about the near certainty that we humans lack free will. At least, as it is normally considered to exist.
Meaning, almost everybody who believes in free will considers that it means we're able to choose one thing instead of another without any causal influence affecting that choice.
Tonight I pondered whether to have leftover spaghetti for dinner, or to make tempe with rice. I decided on the tempe and rice. I had some reasons for that decision. This means that my will wasn't free, since those reasons influenced my choice.
In fact, this is always the case. There's absolutely zero evidence that the human brain is able to act or choose without being affected by prior experiences, brain states, the condition of the world, and such.
The only way free will could exist is known as compatibilism. And this way negates free will as it is commonly understood.
Those who believe in the philosophical notion of compatibilism say that as long as a person isn't constrained by outside influences, such as someone holding a gun to my head and saying "You must choose to have spaghetti tonight," then that person is acting freely.
But this is a much watered-down version of genuine free will, which is viewed as the ability of a human being to choose between two actions, thoughts, or whatever in a way that is unaffected by the inward and outward state of that person's reality.
In other words, neither the person's brain nor the external world has any effect on the person's choices. Those choices are made through some sort of unexplained supernatural Free Will Fairy Dust, which is such an absurd idea, I reject it (almost with most neuroscientists).
One big reason why I don't believe in free will is that I much prefer reality to unreality. I'd rather embrace an uncomfortable truth than a comfortable falsehood. That's why I no longer believe in God, soul, life after death, and other fantasies that used to give me comfort in my true believing days.
It's impossible to live a "spiritual" life, leaving aside the thorny question of what that word means, if that life is founded on untruths. Thus science is the cornerstone of any genuine search for meaning.
Imagine if we still had a medieval understanding of how the universe came to be. No knowledge of the big bang. No knowledge of the astounding vastness of the cosmos. Our worldview would be hugely constricted compared to the modern understanding astronomers and cosmologists have gifted us with.
I see a belief in free will as being similarly constricted. It imagines that each of us is, essentially, the "god" of our own thoughts and actions that are created by us independently, freely, out of nothing other than our own unfettered ability to choose between this and that.
Believers in free will typically don't try to justify their belief. They just accept what seems obvious to them: "It feels like I can choose freely, so that must be so." Of course, it also feels like the sun sets each day, rather than the sun standing still and the earth revolving.
The truths of science take quite a while to filter down into widespread understanding. So I look forward to the day that free will is viewed as akin to the earth-centered cosmos: a mistake caused by a superficial knowledge of reality.
Consider all the findings of modern science: physics, chemistry, biology, psychology, sociology, and so many other disciplines. These countless findings all have something in common. Regularities rooted in the laws of nature and other forms of causes and effects.
There is no finding that free will exists, because if it did, this would be the only instance of an effect occurring in the everyday world without any cause. (I said "everyday" because arguably some quantum effects in the subatomic realm occur without a cause, though even here the wave function is a cause based on probabilities.)
Thus the interconnectedness of our universe, the marvelous oneness where causes and effects multiply without end across not only our planet but the vast expanse of time and space beyond earth, all that is not only compatible with the lack of free will, it demands it.
Free will is a medieval'ish bastion of human separateness, specialness, individuality, and isolation.
Believers in free will imagine that they are islands of unfettered action unto themselves, rather than what we humans actually are: beings who are an integral part of everything in existence, both affected by everything that surrounds us, and affecting everything that surrounds us.
What I or you or anybody does isn't based on our individual self. Every thought and action, no matter how small, requires an entire cosmos to carry out. My fingers typed this blog post, but the words and ideas didn't spring from my free will. They emanated from elsewhere.
Understanding that "elsewhere" is what science is all about. Also, in my view, what spirituality is all about. We don't need to imagine supernatural realms beyond the physical to have a grasp of our place in the oneness of the cosmos.
That oneness is right here, right now. And in large part it is glimpsed by giving up a belief in free will.