See also:
What is a mathematical description of free will?
Is free will reconcilable with a purely physical world?
What is the difference between free-will and randomness and or non-determinism?

The world is either deterministic of non-deterministic.

In the case of determinism, all of the actions are predetermined, so one cannot really choose one's actions. In the case of non-determinism, actions are also determined by some randomness and this randomness is a true randomness, not something that's depending on a hidden mechanism of any kind.

It is often argued that non-determinism allows for a free will. However, the randomness it contains, that would give a place for a free will, is a true randomness, so it isn't being chosen by anybody, it's just purely random.

From that perspective, it appears that "free will" is an ill-defined concept. Are there any better (more useful) definitions?

  • "In the case of determinism, all of the actions are predetermined, so one cannot really choose one's actions." - I don't think that's a given. Choice doesn't mean an absence of predetermination, does it? I understand what you're getting at and the value of defining "free will", but maybe defining "choice" and "choosing" might be a simpler more focused task and just as useful in this context. Just a suggestion.
    – obelia
    Commented May 21, 2014 at 6:24
  • Unfortunately this question and slight variants of this question has been asked many times. I will put this on hold as a duplicate so that all the answers to this same question can be put under one question. :) There are many good answers on the other questions, I would encourage you to read those as well as the answers you've already received here. :)
    – stoicfury
    Commented May 21, 2014 at 16:11

2 Answers 2


Thinking about philosophical issues in terms of definitions is a mistake. Definitions are useful as abbreviations for discussing explanations when you understand the relevant explanation. So then the issue is what role does free will play in our explanations?

If a rock falls off a mountain and kill somebody nobody will prosecute the rock. If a person pushes a rock so that it falls and hits somebody then we may prosecute that person because he had free will. What is the relevant difference? The rock will fall if and only if it is set up in the right way. Nothing we do to the rock can change that. By contrast, how a person will act depends on what knowledge he has and it is possible for him to learn different ideas than the ones he has now - to change his mind. If he has not learned that murder is a bad idea then there is some flaw in the ideas that he enacts that stopped him from learning. And until he learns differently we may reasonably expect that he might murder somebody else. Determinism being true doesn't stop people from having ideas and acting on them. It doesn't stop us from talking to people who do stuff that is bad or foolish, or from locking them up if they pose a threat.

At this point the usual objection is "but that's not what people mean when they say free will". The problem with this objection is that you still need a word to distinguish between physical objects that can learn and those that can't. You can invent a new term if you want but I don't see the need to refrain from using the term "free will" as an abbreviation for the explanation I gave above.


I believe there are two conditions needed for free will:

  • mind state to be independent of the underlying physical state
  • mind state to affect the physical state

The first prerequisite is to break cause-effect cycle. True randomness alone, can satisfy that one, but not the second.

Check the ideas of Roger Penrose on the matter -- he considers the possibility that the process of decision making works on quantum level.

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