In this context, I define free will to mean that a human's high-level actions (not the quantum states of his particles) are not determined, in the same sense that some quantum effects are not determined.

The simplest (hypothetical) experiment to verify the existence of free will would be to observe the actions of a human for a period of time, then "go back in time" to the beginning of the experiment and observe them again, watching for actions that differ from the first run.

Obviously, we can't do that. Is there any conceivable experimental setup that might bring us closer to confirming that we have free will?

  • 1
    $\begingroup$ I would guess that your "in the same sense" is a Pandora's box. Related reading: plato.stanford.edu/entries/freewill, en.wikipedia.org/wiki/Free_will. $\endgroup$
    – Řídící
    Nov 1, 2013 at 11:47
  • 1
    $\begingroup$ Very few physicists are interested in free will/consciousness. A very notable exception, however, is Sir Roger Penrose. You might be interested in his books. See e.g. this section of his wiki: en.wikipedia.org/wiki/Roger_Penrose#Physics_and_consciousness $\endgroup$
    – innisfree
    Nov 1, 2013 at 12:39
  • 1
    $\begingroup$ Also Marvin Minsky has written a lot on this. $\endgroup$ Nov 1, 2013 at 13:35
  • $\begingroup$ @innisfree I'm not sure that Penrose equates free will and consciousness (you don't say that, I know, but your comment might read as such). It seems to me that ultimately consciousness may well become of interest to physicists (or computer scientists or mathematicians): one could imagine scoping out chunks of what we might think of as "consciousness" into reasonably precise terms that we can grapple with, whereas "free will" might be a bit hard to pin down. $\endgroup$ Nov 1, 2013 at 13:36
  • $\begingroup$ how does a person's high level state/actions differ from [the aggregate of] the quantum states/dynamics of his particles? $\endgroup$
    – Dave
    Nov 1, 2013 at 14:51

1 Answer 1


Dogs sniff things and spin in circles before they poop. All dogs do this. It's in their genes. They lick things. They smell food and go after it. It's written in their genetics; it's part of their physical programming.

Humans are the same, although we exhibit more complex behaviors, because our physical brain capacity is greater and we have a rich culture that has evolved over time and is taught to each new person throughout their life. It's like the evolution of genes, except instead of genes being the medium, our living brains and our environment (books, structures, theater, etc.) is the medium.

Free will, in the sense that there's some magical separate "decision entity" is completely bogus. It doesn't exist. There's no need for it. It wouldn't explain anything that isn't already completely explainable and obviously physically based.

As for how our choice of action originates; it's a complex system, but physically based nonetheless.

Depending on where we are at any given second, and given what we learned over our lifetime and what we expect to happen, and how those expectations interact with our immediate and long-term needs, we make choices. I am sitting here typing this, but I'm also thinking about my job and survival, and I have feelings of hunger, and knowledge about my daily routine, etc. I'm constantly making predictions, planning, and feeling things. Thanks to a highly consistent universe, such planning and predictions keep me alive. Partly written into my genes and partly learned from the environment.

There's always something going on in the body and the brain. Always, even while sleeping, as long as you're alive. I'm bombarded by advertisements, other people, sounds in the environment, my dog, airplanes, sunlight, clouds and shadows, the furnace kicking on, etc. Levels of chemicals rise and fall and shift and change according to genetic programs and physics. When I get so tired I can't sit here anymore, I'm compelled to go to sleep or risk going insane. Our environment drives us. Electromagnetic fields interact with our brains, as does everything we ingest, see, hear, and feel. Our choices affect us further in a feedback loop. The kind of free will you're thinking of simply does not exist. It doesn't even make sense to propose it. We are what we are.

That's one of the reasons I say that personal responsibility is a bogus concept, at least in the sense of blaming individuals for their actions, using them as scapegoats, when the true nature of problems are distributed in nature. When we blame individuals for their actions, we erroneously absolve everyone else from playing any part, and that's a mistake. We miss the opportunity to find the real sources of problems, like economic inequality, brain tumors, genetic predispositions, etc. It's just simple-minded to judge people for what they do without looking at the bigger picture.

  • $\begingroup$ Short answer is.. I don't think it's a scientific hypothesis to begin with. What observations lead you to think that the brain and body alone cannot be responsible for peoples choices and behaviors? As far as random events in brain cells go at low-levels, those are present constantly anyway... small vibrations in the ground, radiation, particles in the air we breath in. There's a lot of randomness anyway; no quantum phenomena required. $\endgroup$
    – Triynko
    Nov 1, 2013 at 13:05
  • $\begingroup$ A what, they spin in circles before they poop? $\endgroup$
    – Andersi2
    Nov 1, 2013 at 13:20
  • $\begingroup$ "free will...is completely bogus" - is that broadly accepted in contemporary philosophy or neuroscience? Regardless, I think this question and answer ought to be migrated. $\endgroup$
    – innisfree
    Nov 1, 2013 at 13:33
  • $\begingroup$ Good answer. Actually there is a short documentary by Stephen Hawking that addresses free will and your answer reminded me of it (can't recall the name, sorry, it was something I saw on a 15 hour plane ride). He didn't quite dismiss it as "bogus" though: although ultimately illusory, an approximation that we'd normally call free will drops out as an emergent phenomenon that seems very real and, as you touch on with "predictions [that] ... keep me alive", it's often important to treat it as though "real". Anyhow, the doco was a neat mix of science and philosophy. $\endgroup$ Nov 1, 2013 at 13:35
  • $\begingroup$ Yes, dogs spin before they poop, lol, the same way they spin in circles before they lay down. See answer 4 here: scienceline.ucsb.edu/getkey.php?key=1314 They are basically making sure the area is safe and there aren't any snakes or anything that will jump up and bite them when they are vulnerable. May also have to do with just making their mark more obvious. As far as free will being bogus, I was talking about the idea that there's some independent force external to the body making decisions for us. That's bogus. But the feeling of free will is real, because we are conscious. $\endgroup$
    – Triynko
    Nov 1, 2013 at 14:23