One of the most difficult concepts to grasp is the idea that free will, the cornerstone of our human experience, might be nothing more than an illusion. That may sound like an outrageous claim, but the truth is that it's rooted in mainstream science. To get specific, by free will I mean the ability to choose otherwise given the exact same state of the universe. It turns out this concept is as unscientific as magic.
It works like this: we exist in a deterministic universe, governed by the laws of physics, and the atoms in our bodies are no exception to this. Every part of you, from your DNA, to your life experiences, stems from a previous 'step' in the universe. You didn't choose your genetic makeup or your upbringing. And the subjects you discuss in conversation, or the thoughts in your head, are triggered by other things you've heard or read. In essence, your thoughts, decisions and actions are a result of a complex chain of events you have no control over. Your brain no more chooses it thoughts than your heart chooses to beat.
Why do we believe in free-will? The only evidence we have for it is that we feel it so keenly. Yet this has never been a good measure of reality, our senses are notoriously unreliable. Vision, for example, is predominantly a simulation. Studies demonstrate that when we glance at something new, our sight temporarily shuts off and then reactivates, filling in the gaps with a simulation. The fact that we feel free will so strongly doesn't make it any more real than the many other illusions our senses create.