Is there a definitive answer to the problem of free will as follows: How can free Will exist while physics laws tell us (as well as causality) that every state at any given time is the result of the previous states and governed by unchangeable physics laws of nature? I understand in the field of quantum mechanics, there exists uncertainty principle, but it, at best, results in unpredictable states and still does not give us a proof for freewill. Also, some scholars have pointed out “chaos theory” to address this problem and justify the co-existence of freewill and predetermined physics states, but I have seen some good criticisms on this reasoning as well. I am not sure if I am lost in these arguments or there is no definitive accepted answer yet. Thank you all

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    "Is there a definite [maybe: definitive] answer to the problem of free will ?" No; there are no "definitive answers". – Mauro ALLEGRANZA Oct 1 '20 at 12:44
  • @MauroALLEGRANZA thanks. What is the dominant accepted answer then? – Ebi Oct 1 '20 at 12:48

Two aspects of free will:

  1. Predictability of our brain computation: Our future behaviour can be computed all the way to our death, so in theory, someone can really look at us from the side, knowing what we will do next. In practice however, except for experiments with artificial brains inside artificial worlds, this is not, and will never be possible, due to complexity of both our brains, complexity of outside world and limited computational capacity (almost infinite capacity is needed). Our brain activity is computation, and as a computation it is always is predictable, to some extent, or even fully predictable in theory, for some theoretical super-being. But from our brain perspective, our will is not restricted by being more or less predictable. In normal life we also usually predict what other people will do, that makes their will no less free.

  2. Equivalence of different projections of the same mathematical structure: World described as particle physics interactions is no more "real" or "fundamental", then world described at higher (emergent) levels, by neural activity, or by our choices, therefore by our freewill. Analogy here are waves in the ocean: we can describe particular wave as movement of trillions of individual particles, or we can explain it at macroscopic level, as variations of water pressure. Both descriptions are equally "real", valid and consistent. It is not that particles are more real or more existing then macroscopic wave. It is not that particles are moving wave, or wave is moving particles. Correct description is that physical system is evolving in time and both wave and particles are moving as a result of that.


Lee Smolin is a physicist who suspects that the so-called laws of physics can themselves change. Depending on the level where the laws as such appear, proposals such as changing numbers of space dimensions or changing speeds of light (which do appear in some analysis/conjecture, e.g. one string-theoretic model of the initial expansion involves the extra dimensions collapsing into their presumed small current range) are either examples of Smolin's suspicions or lower-level echoes thereof. Without having to strictly say that the laws of physics changed back then, we still say that the hypothetical inflaton field divided into a gravitational and an electronuclear field, the latter then dividing into the electroweak and strong fields, followed by our current apparent state of affairs where electromagnetism divided out of from the W+/- and Z particle set and photons became an independent force-carrier.

That the rate of expansion appears to have dramatically changed very far down the road of history, might also be taken for slight evidence that the structure of our universe isn't fixed in the way that an overarching determinism would have it.

But now on another level, determinism doesn't always require laws of physics, it just requires that whichever function is working at some time, only has one output for its relevant inputs. For such functions to fundamentally yield, at random, any of multiple possible outputs (specifically possible for the function at a given time), would be for there to be indeterminism with a law of physics (even if that law is highly localized and temporary), perhaps. There doesn't seem to be anything absolutely self-contradictory about a function such as, "f(x) = {x + 1} v {x + 2}", even though if we asked, "Why did the function satisfy the first disjunct this time?" we would have no such answer (if the function were primordial enough, say).

If we have randomly disjoint output possibilities, could we have freely willed ones? How far apart are randomness and free will? For I've seen it said, "Something that happens at random is not the result of free will." This could be that a given action that was freely willed, is the result of that will and not randomness. But a prior action, internal to the will itself, I could see as random but freely willed, maybe. Or: depending on the relation between free will and free choice, I might see there being a choice between random and determined action, with the choice itself neither random nor determined (i.e. it is a category mistake to describe free will internally as random or determined; only its effects count as such).

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