Let us assume that randomness does not exist. For example, even the flip of a coin is not considered random. The coin's flip can be calculated if certain variables are given (the force used for the flip, air resistance, distance from the ground, etc).

But this would imply that no action is completely independent of another action. Meaning an action that occurred millions of years ago can be the cause of a seemingly unrelated outcome today.

Since all actions are a result of previous actions, this would mean all actions are the result of the very first action (whatever that action was).

By this logic, is every single action that has occurred after the very first action up to now predetermined? Wouldn't this imply that all events to take place in the future are also predetermined and can be calculated?

This suggests that every single action we perform can be traced back to the very first action. So does the non-existence of randomness also imply the non-existence of free will?

Note: I know that there is still debate regarding the existence of randomness. It has been noted that behaviors at a quantum level appear to be random. But one could argue that we are mistaking inadequate data for random behavior. But then I am not a quantum physicist, so I do not have nearly enough knowledge to comment on quantum physics.

Either way, my question is about the existence of free will in a universe where randomness does not exist, rather than whether or not randomness exists.

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    Even if quanta are not random, the behind the scenes variables are unknowable, especially if it is the result of infinite universes all interacting with the same, shared gravity. If that isn't sufficiently random, then random holds no meaning anymore. Commented Mar 24, 2015 at 22:10
  • Btw I'm not arguing against anything, just reinforcing that the universe is sufficiently random enough for us to never make a perfect model of it. This has less effect on the macro, and more effect on the micro, such as neurons. I'm not quite sure I'm up to date on what free will means, since we don't have control of a lot of things that we say, think, or do. Whether we do or not may not be relevant though. The questions that lead to the question of free will may be what is relevant. Maybe the whole concept is just an abstraction, and shouldn't be used to base a decision off of. Commented Mar 25, 2015 at 0:22
  • ...if certain variables are given (the force used for the flip, air resistance, distance from the ground, etc). Since it's known to be impossible to know all such details, why ask about circumstances that assume such impossible knowledge? (It's hard enough just knowing both position and speed of a single particle.) The impossibility of knowing is the foundation of randomness. Commented Mar 25, 2015 at 0:57
  • If you mean to ask a hypothetical question (and one where we already strongly believe the opposite), you should clearly indicate that the premise is given with language such as: "Let us suppose that randomness does not, in fact, exist." If you say, "It is believed that (something wrong)", the natural response is "but that is wrong, (evidence evidence evidence)--neither you nor others should believe that!".
    – Rex Kerr
    Commented Mar 25, 2015 at 3:30
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    Having free will means nothing more than not knowing yourself what you will do (or will want to do or will try to do) in future. Even if all of your actions are perfectly known beforehand to everybody else but you you still have free will. Commented Mar 27, 2015 at 19:52

12 Answers 12


Well, there is an ancient and unsettled debate between libertarians who believe free will is incompatible with a deterministic (or random) universe, and compatibilists who believe the libertarian notion of free will is incoherent, and propose a definition of free will which is compatible with a deterministic (or random) universe.

You can read about this debate here: http://plato.stanford.edu/entries/freewill/

I also recommend a good book called "A Contemporary Introduction to Free Will" by Robert Kane.

I would just like to note that while I don't believe the universe is deterministic (why should it), randomness does not help, since random behavior is not any better than deterministic behavior when it comes to free will or responsibility.

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    Thanks for bringing up an important point, which is: random behavior does not solve the problem of free will in physics. People often don't understand/acknowledge this point.
    – cody
    Commented Mar 24, 2015 at 21:56
  • +1 Responsibility is the only decision that comes to mines when asking about free will. Then the people that asked the question, then gave up on life, can be measured against the people that never asked the question, and we can then determine that it's better to not think about it, and put the people that do think about it on a watch list. Commented Mar 25, 2015 at 0:40
  • what is your understanding of free will?
    – yamm
    Commented Mar 25, 2015 at 12:39
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    @YannikAmmann, I am bipolar on free will; on the one hand, I am comfortable with free will being an illusion - where my consciousness is a passive watching of an ever changing inner and outer world; on the other hand, I strongly believe that my consciousness is unfathomable and beyond computation, and that an "incoherent" libertarian notion of free will may be how consciousness interacts with the physical - If you happen to believe consciousness is reducible or may be simulated, as most people do, you probably find this ridiculous; that's ok, I don't mind.
    – nir
    Commented Mar 25, 2015 at 19:47
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    On the fact that randomness doesn't imply free will, I like to use the analogy of Snakes And Ladders. It's random, but you still don't get to make any decisions.
    – Jack M
    Commented Mar 25, 2015 at 22:40

I've posted this one a few times. Define "free-will" and you can progress towards an answer.

The simplest form of "the freedom to choose ones actions" is rapidly disproved by someone locking you in a small box. You clearly do not have the freedom to walk out and observe a sunset. Thus any meaningful version of free-will will recognize that free-will is not complete freedom to do anything without concern as to the environment around you (and the actions of others). There will always be some interaction.

The second issue to deal with is what has "freewill" in the first place. What defines such an entity? Clearly you have very limited freewill to do things which are contrary to what your brain-state was a few microseconds ago, so there is some concept of an envelope defining an "agent" which has freewill. That exact definition is important for combining determinism with freewill because you're going to have to track that envelope back through time to make sense of the two of them. Does your self-as-agent begin at conception with no size, or do you include some of the state of the sperm and egg? If you include those, you can track all of that back to the beginning of time. By this particular definition of an agent, you have freewill because "you" were there right at the beginning (albeit it was a pretty darn rough ride until time progressed long enough to give you a body).

There are plenty of other directions to look, and other models. However, I have found definitions for "free-will" and "self" are essential for any systematic analysis of freewill. Pick your definitions, and work from there.

  • ""the freedom to choose ones actions" is rapidly disproved by someone locking you in a small box" -- touche! Even more remarkable is how you choose to illustrate that point because that's exactly where we start metaphysically! "Cogito, ergo sum" being the only truth we will ever know leaves us with an infinitude of the different ways we can interpret perceptions. Except impossible is nothing means nothing is possible, so here we are -- locked in a small box... for as long as we stay rational. We must, therefore, make it a leap of faith. . . . Commented Feb 7, 2021 at 12:53
  • . . . Like the proverbial drunkard searching for his key under a streetlamp, we leap toward the light, the only place we can find the Truth -- we assume the possibility of doing science. We assume our reality being deterministic and, thus, explainable. And not just explainable, but by us, humans. And not just by us, but the way a grandma would understand -- or a ten-year-old girl, or anyone in between... Then we will know the Truth, and the Truth will set us free. Commented Feb 7, 2021 at 13:10

It seems to me that there are unstated implied assumptions in the question, which are more material to the answer, than those in the question itself.

A coin flip is only relevant to animal free will, if one takes some of these assumptions in particular ways that make them relevant.

Theoretical knowability of everything if one somehow had all the parameters of everything, seems to me a far less useful and reasonable perspective, than accepting unknownness and effective randomness. Insisting on mechanical determinism of everything seems to me unbalanced in the direction of an obsessive and impossible need to know everything, perhaps to relieve an anxiety of being unable to control everything? In any case, the connection to free will seems to me unclearly stated.

Denying free will also seems to me not less useful than its alternative. I would say that people clearly have free will on the level that we experience it, and arguing that an impossible all-knowing model of everything could predict someone's choice... seems to mainly have the point of provoking emotional responses based on a misunderstanding of what the suggestion actually is.

On the other hand, inasmuch as conciousness, will, souls and spirits are largely undefined by most deterministic theories that try to model everything, I think it is a somewhat interesting question. What if the material universe is all that can be mechanistically modeled, but our subjective experience is outside that, and has input into our actions? What if there is not one universe timeline, but an infinite range of possibilities, and making a choice of action merely changes which possibility our consciousness follows? That's interesting to me to speculate on, but isn't really answerable either.

  • If will is that what makes me act in a certain way, then it seems this is already something complicated, the result of different mental actors: There seem to be reactions, like unvoluntary movements, which are beyond my conscience. Also my conscience seems to have modes more emotional or more rational or the stomach feeling. It seems reasonable that different parts of my brain and nerves are involved and who knows there is some acting part which is non-physical (soul, spirit, dark energy, whatever).
    – mvw
    Commented Mar 25, 2015 at 16:58

A world without randomness presupposes many things and is impossible to assess, but assuming that the only thing that has changed is our knowledge that the world is not random we can then try to evaluate free will. So, what is free will? For the sake of argument, we can call it the ability of agents to make unimpeded choices. Obviously all choices are impeded to some extent by our experience, but we want to know whether randomness is what allows our choices. This is where the premise is obviously silly. Randomness has no logical connection to choice. Just because I make a calculated decision, one that is not random, would not inherently mean I did not make the decision. How can I make a particular choice, if my choice is random. Agency, is far more deep and controversial than a debate between randomness and determinism. For instance, what determines our actions are often well illustrated as not random, in fact in social science and psychology we often see the causation behind action, but that does not necessarily take away agency. For example, I may choose one job over another because of very concrete, non-random reasons like salary (a value shown by society), but that does not inherently mean I didn't make the choice unimpeded. If I randomly decided which job, I would not illustrate free will, all that happened was chance.

Second, even if my choices are caused by non-random circumstance, that does not mean that circumstances do not create agency. Physical reactions may create a quality of agency as defined above that then follows non-random behaviors.

Finally, we live in a world with more or less free will. For instance, a trafficked prostitute has more agency than a prostitute that is not trafficked (much of this is determined by the discourse of how states define women and prostitution). In the most meaningful way, one person can have less impeded choices than others, which illustrates, regardless of randomness or determinism, free will.


This is basically one of Aquinas's arguments. It is only valid based on the Aristotelian physics he was using. And in the end he comes down against it. He widens the logical gap in Aristotle with some vocabulary, and uses it as a place to insert a proof of God.

Even under Newton, forces can be equally balanced and the determinants of those forces can also and so forth and so on. Newton himself believed in a certain determinism, but in deciding that he relied way too much on the convergence and continuity of functions. He has a basic assumption that all of calculus applies to all circumstances. But our modern view of calculus is that real functions of motion may often not be smooth enough for its products to be well defined.

Even any useful complex functions (the most staid and predictable domain) beyond polynomials have poles and essential singularities forced on them -- one can imagine that knowing the value of some attribute lies in a tiny region wherein the function takes values of every magnitude can be done deterministically, but in my book that is presuming the conclusion and then just insisting on it.

From a more classical viewpoint, if one is intellectually honest, the only way out of Zeno's paradox is nondeterminism. What happens when things are in perfect balance depends on some higher moment, (or influences from farther away or farther back in time) and if those are balanced, it depends on a higher one still.

Aquinas' answer to Zeno's paradox (in the First Way) is God, Newton's was uniform infinite differentiability of functions that are reciprocally or iteratively defined (which many mathematicians consider unlikely). In my book, both are cheating. Ours, now, is generally nondeterminism. Motion is possible because the lack of motion is impossible, and that mandatory motion, is at its root, utterly random.

Even if physics were determined entirely by mathematics, from this perspective the math itself is not really strong enough to support a deterministic worldview in complex situations. We can make approximations, but they become bizarre and break, fairly easily, and then we just assume there are better approximations because it is in our experience that this is what works. But the math does not say there are really better ones to make. It just says you can insist further as much as you want. Really a lot of things remain undefined. At small enough scale, Heisenberg suggests, it may even be required that they remain undetermined.

It is nice to suppose the world is really like humans naturally imagine it, but we need to pay some attention to the data.

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    This is a misunderstanding of chaos theory - the whole point of which is that deterministic systems may be effectively unpredictable. Systems with strange attractors are deterministic, but exhibit sensitive dependence on initial conditions. Arbitrarily small discrepancies in the initial conditions become arbitrarily(ish) large discrepancies in long-term behaviour. Given perfect knowledge, chaotic systems are still predictable.
    – RAOF
    Commented Mar 25, 2015 at 22:41
  • So the existence of equally balanced forces is absolutely impossible? If not, then to have determinacy, you are supposing your functions are smooth to a totally ridiculous degree, and functions in general are not.
    – user9166
    Commented Mar 26, 2015 at 18:15
  • Newton's picture of functions was basically infinitely differentiable, our picture of functions is not, due largely to chaos theory. This is not a misunderstanding. I will edit out the reference, but I have not misunderstood.
    – user9166
    Commented Mar 26, 2015 at 18:23
  • Um, chaos theory works on infinitely differentiable functions just fine - the famous “butterfly” Lorentz attractor appears in a system of three quadratic differential equations; they're certainly infinitely differentiable (although boring after the 3rd differentiation, because they're identically 0).
    – RAOF
    Commented Mar 27, 2015 at 5:25
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    Modern mathematics absolutely does not suggest random behaviour. Chaos theory suggests behaviour that is unpredictable without perfect knowledge, but that is very different to random behaviour. As your “ball balanced perfectly on a hill” example itself demonstrates - if it's exactly balanced then it won't fall down, and if it's not perfectly balanced then it's only our imperfect knowledge of which side it's on that prevents us from predicting which side it'll roll down.
    – RAOF
    Commented Mar 27, 2015 at 5:26

Q: So does the non-existence of randomness also imply the non-existence of free will? (*)

To avoid more misreadings, some definitions:

Randomness means lack of pattern or predictability in events. (Wikipedia)

[..] we shall define determinism as the metaphysical thesis that the facts of the past, in conjunction with the laws of nature, entail every truth about the future. (Stanford Encyclopedia of Philosophy)

I equate a world without randomness as a fully predictable world, thus a deterministic world.

Note that our world seems to be somehing in between, e.g. the solution of the Schrödinger equation of an electron of a hydrogen atom gives a probability distribution of its positions. It is neither fully random, because the electron will over time be found at positions in accordance with expected probabities, they form patterns. Nor is it fully deterministic, because we have no means to predict the future positions from the past information.

So the answer to your question (*) is:

A: If the additional condition holds that will is determined by the world then if the world is deterministic then the will, which is determined by the deterministic world, is deterministic as well. Then there is no free will.

Initial states and time propagation laws would determine the future states including the states of mind.

Important here is the relationship between mind and the physical world, e.g. see the :

The mind–body problem in philosophy examines the relationship between mind and matter [..]

A variety of approaches have been proposed. Most are either dualist or monist. Dualism maintains a rigid distinction between the realms of mind and matter. Monism maintains that there is only one unifying reality, substance or essence in terms of which everything can be explained. Wikipedia

Example: The functionality of a computer program is based on physical state, esp. the contents of its main memory, state in the processors and hardware devices. We can save that state and at a later time reload it and have the system continuing exactly from save time. (This is commonplace today in guise of a sleep function or in virtualization software)

If we had a device that would be able to record all matter within a certain volume and its state and then at another position and/or later in time be able to recreate all matter and enforce the recorded state, we would expect a working copy of the computer at the second location and or second time.

However if one would use the same device on a living being or a human, the result could be interesting, depending on life and the mind to be completely described by the matter in the volume and its state. In both cases we do not know if that would suffice. Or maybe the mind is a non-local phenomenon, then the limited recording volume could be cause of not getting a pefect copy.

Q: Wouldn't this imply that all events to take place in the future are also predetermined and can be calculated? (**)

Taking the above described position this would yield the answer:

A: Having the full knowledge of initial states and laws, one could calculate the future states.

Could we do this? Most likely not, because we are living in a world which seems not fully deterministic, we have only finite resources and time (both limiting our computational power) and have no full knowledge of the initial states and laws.

  • This does not provide an answer to the question. To critique or request clarification from an author, leave a comment below their post.
    – iphigenie
    Commented Mar 25, 2015 at 16:02
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    Clearer, yes. Although, if you compare your answer to the highest voted one, you'll notice that yours is still lacking. It doesn't cite or give references, and also you're taking premises for granted that aren't (e.g. that the will is subject to determination as everything else).
    – iphigenie
    Commented Mar 25, 2015 at 17:13
  • I tried to address your additional critique.
    – mvw
    Commented Apr 2, 2015 at 11:25

So does the non-existence of randomness also imply the non-existence of free will?

Amazingly, the opposite is true: free will, as a conscious choice, is only possible if:

  1. The Reality is deterministic and, therefore, fundamentally explainable1


  1. Our brains are hardwired with all the rules of "logic and reason",2 as well as 3-d geometry, making it possible for us to explain the creation, the real world outside

Armed with that understanding we can learn our options, thus making it a conscious choice.

1 "Through [the Lógos] all things were made; without it, nothing was made that has been made" -- John 1:3, "lógos" means "logic and reason", or "reason as faculty".
That being said, I can't deny that I might teleport/tunnel in your bedroom, in part or in whole, before you finish reading this sentence. In other words, yes, miracles do happen. Still, given their negligible probability, we should, for all intents and purposes, treat the Reality as reliably deterministic.

2 the meaning of "being made in God's own image"


One cent.

Libertarian free will requires the negation of determinism, that is, "not all events are determined" (some events can be completely determined though). If randomness is meant as "not predetermined" then (libertarian) free will requires this kind of randomness. If randomness is meant as something else, for example, "(algorithmically) unpredictable", then randomness in this sense may not be necessary indeed, since an outcome of free will, if exists, can be as predictable or unpredictable as wished.

So, to sum up, it depends on the notion of randomness employed, whether it is required for (libertarian) free will.


The concept of free will states that you can make a decision by yourself. The problem is that you are always influenced on your decision. If you would have to make the same choice twice in the same environment you will always make the same decision because somehow you came to the conclusion on what to do. So it would be deterministic.

Post i made about determinism

Because there is a lot of stuff we don't know about the universe especially how or why it became in the first place we cant make real assumptions about determinism just observations.

Ergo: Lack of randomness implies the absence of free will.

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    I don't see your logic. Because determinism is difficult to observe, randomness is free will? See most of the posts made here. Randomness has no inherent link to free will. It just means our choices are impeded by chance rather than calculable forces, it does not mean our choices are less impeded.
    – alfonso
    Commented Mar 25, 2015 at 13:18
  • I don't think that the first paragraph makes any sense at all. I make lots of decisions for no particular reason at all. Given the same choice twice in the same environment, there's plenty of situations where I absolutely won't make the same decision. What I order for lunch 2 different times at McDonald's is the first example that comes to mind.
    – Dunk
    Commented Mar 25, 2015 at 16:16
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    We have simply no idea if the mind is determined by physical state only. It could have internal state not subject to those of the physical universe, state influenced by other minds, many random generators or be even more weird.
    – mvw
    Commented Mar 25, 2015 at 16:21

In a very, very theoretical sense, I'd agree with you.

For instance, as a computer scientist, I could write a program that will calculate what you will eat for breakfast tomorrow morning. The input would be everything you've ever experienced, your genes, your environment, etc... Hypothetically, I would need a complete "copy of your world."

After my super computer spends 9 billion years taking everything that may have influenced you throughout your life into consideration, it turns out that you are eating eggs.

However, your decision was based 98% on the fact that there were some dope eggs on the food network the night before, 1% because your body is lacking a nutrient obtained from eggs, and infinitely small percentages of everything else in your life - all the way down to that first action. (You could argue that first action is actually 100% responsible, but I digress.)

By one definition of free will, this program actually calculates what you will do with it in your life. (i.e., the choices you are free to make as an individual, given your influences) On the other hand, it does imply that there was never really any free will at all.


You have it right. That's exactly the way it works.

Also what might be of interest is a concept called the backwards light cone.

Which is just a fancy way of pointing out the search area of where you can get information to predict an event exactly.

For example say that you are flipping a coin and you have all the information you need to predict what side it will be facing up when it lands, but then right at the last flip in the air before it lands the sun comes up. The first ray of light from the sun and the photons from that light hit your coin and the energy from those photons are somehow just barely enough to make the coin flip to the other side of the coin than what you predicted.

Because the speed limit of the universe is the speed of light then the backwards light cone tells you that as long as something is farther than the time it would take to reach what you are trying to predict at the speed of light then you don't need that extra information.

Sunlight takes 8.3 mins starting at the surface of the sun to reach the surface of the earth. Light from Alpha Centauri takes 4.37 years to reach earth. In order to get all the information to predict some future event using the backwards light cone you know that you can figure out the maximum distance that something can be from your event in order to have an effect on the outcome.

edit: You mentioned that it's possible that particles in Quantum Mechanics don't behave randomly, the name of that idea is Bohmian Mechanics and has the key feature that there is a hidden variable that explains QM without randomness.

  • The past light cone is indeed an interesting limitation of the universe. As the past light cone at position X is different from the light cone at position Y (where X <> Y), it means there could be a different first cause for each light cone. Also extending the light cone to the past has to stop at the birth of the universe or if its spatial area exhausts the size of the universe at that past time. Mind boggling.
    – mvw
    Commented Mar 25, 2015 at 16:25

If we assume that randomness does not exist, then we assume that every apparently random outcome is actually not random at all.

The logical opposite of random is deliberate. The assumption that nothing is random means that everything is deliberately decided. If there is no randomness, then everything happens according to someone's free will. Exactly. With absolute accuracy.

If you are given the task to pick one card from a full deck, you have exactly two options: Either you deliberately select the card of your choice or you randomly pick one card face down. If you eliminate randomness, then your only choice is to deliberately choose the card.

  • If we don't insist that "deliberate" necessarily implies prepense, pre-consideration, then the conceptual gap between deliberate and random gets narrower. This is where spontaneous action, which looks as random and self-determined at once, resides.
    – ttnphns
    Commented Feb 7, 2021 at 5:55
  • Deliberate necessarily implies a decision. Spontaneous actions are decided actions. If they look like random, they look like it by choice, i.e. they are pseudo-random. Commented Feb 8, 2021 at 8:32

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