I think scientists agree that we're conscious and aware that we have consciousness and awareness. But they don't agree on whether we have free will. I think they don't even have a universal definition of the term, so, for the purposes of this question, I want to attempt to define it as the ability of the "conscious component" of us to affect our body. (I'm not sure how little sense this definition makes, but I hope it's able to convey why I'm asking the question.)

Moreover, I hope scientists agree that consciousness is a quality that was selected for over the course of our evolution starting, at the beginning, from unconscious simple molecules.

My question is: If we don't have free will, why was the quality of being conscious selected for? What advantage is there for being conscious of our environment if the conscious part of us has no way of affecting our physics/biology?

  • We don't exactly understand how natural selection, and physics/chemistry go together. The Miller Urey experiment is the most we understand at the moment, but even that doesn't give any details of mechanism. So all we can do is speculate a lot. Commented Jun 10, 2018 at 17:20
  • People like Sam Harris who advocate unfree will, see it as a useful subjective illusion. I am inclined to see as mainly a language and category problem.
    – CriglCragl
    Commented Jun 10, 2018 at 18:27
  • Why do you assume it was selected for? See: newscientist.com/article/…
    – Chelonian
    Commented Jun 11, 2018 at 14:57
  • This question is not addressed in biology. Clearly we started to stand upright and walk because we wanted to, but the 'wanting' is not part of biology. Schrodinger discusses this issue in his essay 'What is Life?' One thing - If consciousness affects our 'physics/biology' this need not mean we have freewill. . .
    – user20253
    Commented Aug 30, 2019 at 10:44
  • The question poses an interesting problem, but to frame it in terms of natural selection, is not the best way to phrase it. The main question is why consciousness without free will, since it is clearly useless exists? And this is an importanrt question,that can be turned into an argument, since as far as we know so far, everything existing serves something. Nothing is only there for decoration, having no effect whatsoever. So if we agree on consciousness, free will can follow
    – Nikos M.
    Commented Jan 19, 2023 at 22:07

7 Answers 7


You may have written yourself into a corner. By defining free will to be the ability for one part of our body (the "conscious part," as you coin it) to interact with the rest of the body and the environment, you define "free will" to exist as long as one is conscious and that consciousness can affect the environment. As such, when combined with the claim that someone believes we are conscious, this directly implies that that someone believes we have free will.

The confusion you are running into is that all of the words you are using are notoriously difficult to pin definitions to, but you pinned a few definitions to them. Now you see that it's very difficult to create consistent theories using those definitions. This is the reason why there are not universally accepted definitions of those words: its hard to create consistent theories with those definitions.

This confusion is then compounded by a teleological approach to evolution. When it comes to evolution, the reason why something was selected is not specified. It is stated that the individuals who had this trait were more fit, and thus reproduced better, but it does not specify anything about why they were more fit. We do indeed seek to find after-the-fact explanations, such as claiming that Cicada's developed a 13 year dormancy cycle to outwit predators, but that is merely our model of what happened.

To understand the difference, consider a coin that is flipped 4 times. It lands heads up every time. We may see a pattern of "oh, the coin landed heads up every time." In reality, there was no "why" to this pattern, because it was truly random. But that doesn't prevent us from fitting patterns to it.

Accordingly, it may make sense not to think of it as "Consciousness exists, and we are conscious," but "We exist, and consciousness is the thing we have." The latter points out the reality that we really define consciousness based on what we have. If we had something different, we would define it different.

And so, the best reason why we can say evolution selected consciousness is because we are alive. One can go into modeling, and try to identify traits that we can use to provide an explanation for this (there do seem to be advantages to being able to be aware of your own actions), but that is merely an explanation. Nothing more.


My question is: If we don't have free will, why was the quality of being conscious selected for? What advantage is there for being conscious of our environment if the conscious part of us has no way of affecting our physics/biology?

Your argument seems to be:

(1) If we don't have free will then our phenomenal consciousness makes no difference to our behaviour.
(2) If phenomenal consciousness makes no difference to our behaviour then it provides no evolutionary benefit to have phenomenal consciousness.
(3) If phenomenal consciousness provides no evolutionary benefit then we wouldn't have it.
(4) But we have phenomenal consciousness.
(C) Therefore we have free will.

There are multiple issues. Firstly, if we subscribe to certain ideas in philosophy of mind then this argumentation doesn't apply. If we can link phenomenal consciousness to physical brain processes then no free will is necessary to explain an evolutionary benefit. Only the physical brain processes that determine behaviour would have to be explained evolutionary. This would reject premises 1 and 2. It's the main issue of the implicit argument in your question.

To put it differently: if all our behaviour is unfree then that unfree behaviour can still be explained evolutionary. But then how does this lead to phenomenal consciousness? That's what needs to be explained. There are multiple physicalist ideas to do so. They all have their fair share of problems, however.

Secondly, we could also attack premise 3. You're writing of "selected for". This seems or at least sounds like a misconception of how evolution works. By putting it like this, we make natural selection into a teleological process. (Well, to be more precise, a teleological process of a problematic kind.) But we could also describe it much differently. For example, we might say: if a trait is detrimental to survivabilty (and hence is a evolutionary impediment) then it lowers the chances of passing on the trait; if a trait is beneficial to survivabilty then it highers the chances of passing on the trait. With this view it is perfectly possible for a random trait that only isn't detrimental to be passed on.


The case for agency is trivial

You write:

I want to attempt to define [free will] as the ability of the "conscious component" of us to affect our body.

That already has a name; that is called agency.

Agency is the capacity of an actor to act in a given environment.

Note that Agency and Free Will normally are not considered the same. But in your post you have decided to define Free Will differently, so that it overlaps with Agency.

So you want to know what kind of evolutionary pressure could cause the emergence of agency.

It is trivial to claim that the ability to make an informed decision based on available data is an evolutionary advantage, because that allows intelligence to help protect you and to help you survive long enough to procreate.

This article on Huffpost explores the subject a bit further.


There are two sorts of questions at play here. You use the term 'free will' which is largely subject to philosophical methods, and you use the term 'evolution' which is largely subject to scientific methods. It is important to establish some presumptions, to wit:

1) If you are presuming evolution is a sound scientific theory, then you are conceding the importance of empiricism and scientific methods for establishing certainty. 2) Let us presume that 'free will' whatever that may be doesn't exist. As you haven't defined what 'free will', it might be difficult to draw conclusions from inference regarding that.

My question is: If we don't have free will, why was the quality of being conscious selected for? What advantage is there for being conscious of our environment if the conscious part of us has no way of affecting our physics/biology?

Now, let's set aside any word games that might be played and restate your question as such: why did natural selection select for consciousness?

This is a good question, and may be more scientific than philosophy despite your invocation of the terms 'consciousness' and 'free will'.

Remember, in natural selection which affects descent with modification, the question can be refined to how does consciousness add to extra fitness in reproduction?

Remember, that in evolution, the concept of adaptation has a very central role in understanding evolutionary fitness, and it might be easy to see the extra evolutionary fitness granted by consciousness through example.

If one has two organisms, let us say the mushroom and the mushroom hunter, we can compare their roles in the ecosystem. A mushroom merely grows. It is stationary, does not react to sudden changes in the environment. And largely exists passively. Spores are spread through the wind, and probability dictates if a spore carries on.

A mushroom hunter also grows, but consciousness grants some extra behaviors in the literal sense. A conscious human is not stationary, but can move about the environment in an attempt to fill goals aware of changes around herself. She exhibits intelligent behavior related to awareness. A mushroom hunter can distinguish between safe and poisonous mushrooms, and consume safe mushrooms to ensure survival. Consciousness allows her to move through environment over great distances, and avoid death by other animals, particularly predators. Consciousness allows a female mushroom hunter to pick a fit male mushroom hunter, perhaps against her own impulses based on reason.

So, what advantage? Natural selection favors adaptability, and consciousness (which occurs at speeds less than 500ms) influences behavior by increasing the capacities of intelligence, particularly in a competition with other intelligent agents.

  • I think this answer explains it very well. If a creature has no consciousness it is easy to see that there is no free will and that creature is just reacting to stimuli. If it had the ability to remember one piece of information, say that a particular mushroom made it sick after eating it, that could help it survive and reproduce. Extrapolate that to something that can remember thousands of things and it is clearly an advantage. Take that even further with humans and you have a being who can manipulate people & environment in order to survive and reproduce. But it doesn't mean it has free will
    – grinch
    Commented Aug 14, 2020 at 14:20
  • 1
    @grinch Thanks. If you haven't seen it, your last sentence is best exmplified by the movie Ex Machina, where the criteria for consciousness is much stronger than the Turing test.
    – J D
    Commented Aug 14, 2020 at 14:23
  • 1
    Yeah that was a great movie! And yes, exactly. Just because something can remember lots of things and use that data along with inputs from the environment to make decisions, it does not mean that it had any true choice in the decision it makes. The decision making process is just super complex but still deterministic. Under these exact inputs it comes to this decision. Which might be another reason it is selected for. If something is so complex it is hard to figure out how to manipulate it. Much like how in Ex Machina the human was manipulated by the computer and not the other way around.
    – grinch
    Commented Aug 14, 2020 at 14:27

Consciousness as an evolutionarily-unrelated scaling epiphenomena of non-equilibrium chemistry, formulated under the Free-Energy Principle.


I think the answer lies in the free-energy principle, an emerging mathematical principle in biophysics and cognitive science that describes a formal account of the representational capacities of physical systems, a sort of universal mechanics behind everything from cells to cities (from ordered hydrogen to highly-ordered hydrogen). Understanding the principle in its entirety takes an inordinate amount of time and discipline; however, I will attempt to explain it as simply as I can below. It will be initially difficult to follow, but ties well into consciousness towards the end.


Non-Equilibrium Steady-State Chemical Systems

Given a basic understanding of chemical systems, you'd know inevitably everything goes from order to disorder as per the second law of thermodynamics; reactions tend towards higher entropy, towards a thermodynamic equilibrium. However, there exists chemical systems that resist entropy; these are non-equilibrium steady-state chemical systems. They remain in a dynamic exchange of resources between itself and its environment. If its environment doesn't contain a specific array of resources, the system either remains stagnant or moves towards disorder. The resource specificity is entirely dependent on the system: its structural dependencies.

Free-Energy Redefinition of Chemical Systems

Let's take a step back, and let's use different language. By resisting entropy, the system remains alive. If the system reaches thermodynamic equilibrium, it dies. By resisting entropy, the system can be said to intrinsically contain true beliefs about its environment, built into its structure and encoded inner functionality. If the system reaches thermodynamic equilibrium, the system's "beliefs" are then false. The collection of these "beliefs" is called the system's model; it's the array of the system's inner states representing hidden external environmental states. The system will always act to maintain true "beliefs," to model its environment in order to stay 'alive.'

Different Sensory-Expectation Engines within Organisms

I hope I've kept you up until this point, because this is where it becomes exciting. Let's consider the following organisms: a bacteria, a rabbit, and a human. A bacteria responds to basic external input; however, most behavior is stagnant. For substantial belief changes, the bacteria has to die for the model to update within the population via random mutation. A rabbit responds to more complex external input; however, most behavior is bound to a long reflex arc, genetically predisposed. For substantial belief changes, the rabbit can either die or act within its generality for the model to update. A human responds to drastically more complex input; some behavior is bound to a very short reflex arc, genetically predisposed. Our generality can be said to be greater than rabbits, the spectrum of possible behavior. All action and perception is in the service of minimizing prediction error and maximizing model evidence of the world around us, all behavior is driven by an intrinsic reward to minimize free-energy. We act upon the environment to change incoming sensations to match the model. We update the model to match the incoming sensations from our environments.

My Consciousness Pièce de Résistance

I say this all to say that from atoms self-assembling into molecules to humans both maximizing model evidence and reducing prediction error between their models and the external world, it's all the same mechanics used to minimize free-energy in a non-equilibrium dynamic to resist entropy. I've come to believe consciousness was not selected via natural selection nor does it affect any neural process within organisms; I believe consciousness is an intrinsic epiphenomena of non-equilibrium systems, from ordered hydrogen to highly-ordered hydrogen. All emotion we feel is the conscious awareness of prediction error arising hierarchically within our neural computational circuitry. Our acting and thinking is response to this error, and our experience of acting and thinking is epiphenomenal, an unnecessary consequence of an information-theoretic dynamic exchange between a model and the environment it attempts to understand. I find this answer provides a better explanation than citing supernatural intervention or an incomprehensible complexity.

  • Wherefrom.is the statement that maximum entropy means "death" and minimum entropy means "life". This is an arbitrary subjective interpretation based on misconceptions about entropy as disorder. Even if it is true as stated, in what sense subjective consciousness arises out of far-from-equilibrium dynamics is simply hand-waved, again arbitrarily. Are we to take it as an article of faith?
    – Nikos M.
    Commented Jan 25, 2023 at 21:02
  • Furthermore it has been argued convincingly that subjective consciousness is a feature that cannot emerge from other processes lacking this feature, it has to be there already. In the same sense "length" cannot emerge as property from lengthless processes. In other words emergence can happen only for some features and properties, not all.
    – Nikos M.
    Commented Jan 25, 2023 at 22:02
  • @NikosM. I'm simply providing a novel perspective emerging in computational neuroscience, constructed out of Karl Friston's research. You are exactly right; it has to be there already. To understand the origin of complex neural phenomena, like beliefs and consciousness, you have to accept those phenomena consist of constituent parts. How does self-assembling chemistry come to resemble concepts like belief and consciousness? The emergence of non-equilibrium chemical systems, i.e. abiogenesis, which scalably reduce prediction error via subsequent natural selection, i.e. evolution. Commented Jan 25, 2023 at 23:04
  • Furthermore, this is how I've come to rationalize consciousness. We are only conscious of what's considered prediction error within the free-energy principle. I do take offense. It's certainly not faith; it's a combination of biophysics, reductionism, and some really complicated mathematics. Commented Jan 25, 2023 at 23:07
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    Yes, a definition of belief within this free-energy framing. Not as an array of mental abstractions like the definition conventionally held, but the actual physical structure of the system, from which inputs/outputs are manipulated and hidden environmental states are intrinsically assumed. It's not easy to conceptualize this redefinition; it's almost a new functionalist perspective on cognition. I'm sorry for the confusion. I should've outlined this part further. Commented Jan 25, 2023 at 23:34

Free will is the idea we do what we wish. In an earthly sense, this fits in perfectly creating a society as it is. Jailing the criminals who misuse their free will and crowning the adherers of accepted morality.

Put it in a cosmic sense, and you see the unjustness of said society. Do humans program themselves before being born? No. They don't choose their personality. It is both inherent and changed due to environment. So, if a man doesn't get to choose his own self behavior, his likes and wants, then how is he doing anything he wants? He is simply a randomly generated character playing out a determined life.

Consciousness makes one think they act on their own accord, but actually consciousness plays the said personality that cultivated itself. Freewill is an illusion that flows with consciousness. BTW, true free will is actually impossible.

  • I made some edits for grammar and spelling. You may roll these back or further edit. I tried to keep your intent. Do you have references for positions similar to yours? This would help readers get more information and support your answer. Welcome to the SE! Commented Jun 11, 2018 at 1:10
  • Thanks for that. There's a YouTuber named Cosmic Skeptic. He has a few videos regarding freewill. Besides that, nothing since this idea was mostly self-realized.
    – Hittfler
    Commented Jun 11, 2018 at 1:25

Whether it has free will or not does not matter, consciousness was selected to be in us (and probably in other higher animals) only because it can help increase the chance of our survival. Evolution is the process that selects traits that increase the chance of survival of organisms. It does not care about free will. Our reflexes, autonomic functions, cerebellar functions, and all other functions in our bodies do not have free will, yet they are selected to be in our bodies just because they help increase the chance of our survival.

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