Could you ever have chosen otherwise?

It depends on which of three positions you hold. Libertarians say yes. Some of your choices aren't fully fixed by earlier causes, so you really could have done otherwise. Hard determinists say no. If every choice follows from prior causes, only one path was ever open. Compatibilists say yes, in the sense that matters. You're free if nothing would have stopped you doing otherwise, had you wanted to. In a 2020 survey, 59.2% of philosophers favored compatibilism.

In 1983 the neuroscientist Benjamin Libet brought the brain into it. Volunteers flexed a wrist whenever they felt like it. They watched a fast-moving dot and noted where it was when they first felt the urge. Electrodes picked up a buildup of brain activity, the readiness potential. It began as much as 300 milliseconds before people reported the urge. To some, the brain had started the action before "you" decided anything.

Libet himself read it differently. In later trials, people who felt the urge could still veto it and not move. He concluded his results fit with free will, relocated to a power to stop: "free won't." The philosopher Max Velmans asked why the veto wouldn't have its own unconscious head start. And in 2012, Aaron Schurger and colleagues proposed that the readiness potential may be random neural noise, not a hidden decision.

There's also a limit to what was tested. Libet studied quick, arbitrary wrist flicks, not deliberate choices. He said his evidence didn't rule out conscious control when people actually deliberate. The science sharpens the question. It hasn't settled it.