It seems that physicalism and functionalism in philosophy of mind has fallen out of popularity and into much criticism. I haven't delved too deeply into the literature, but I find it somewhat strange that consciousness, something that I hope we can all agree resides in the mind, and thus subject to the same causal and laws of every other hunk of matter, is now being considered as something in part non-physical.

In short, I don't understand how the mind somehow cannot be thought of as a biological system with properties that allow consciousness as some emergent power. There is nothing more to the physical properties of our brains, and it seems clear that our consciousnesses are closely tied, if not solely tied, to the physical brain, and thus of solely physical and causal laws. What are some of the criticisms of physicalism in philosophy of mind that would deal with my views?

In my opinion, we need to employ some variant of Ockham's Razor and cut out any explanations of things in the natural world that involve any metaphysical appeal. The purely physical explanation of a phenomena is the best explanation. My methodological approach is irrelevant, however, to my question above.

  • 1
    What you describe in the first paragraph is not physicalism but least common denominator materialism, or even just naturalism. Physicalism is a much stronger programme of reducing mental to physical explicitly, e.g. putting some meat on how consciousness "emerges" or is tied to the brain. Since even reducing chemistry to physics, or biology to chemistry proved to be unfeasible for the foreseeable future this programme is currently on ice. Whether physical explanation is best or not we simply don't know how to start approaching it at the moment.
    – Conifold
    May 15, 2016 at 19:23

2 Answers 2


First a comment: I am surprised at your stating that "It seems that physicalism and functionalism in philosophy of mind has fallen out of popularity and into much criticism". All of the philosophy of mind courses and lectures I have listened to state that functionalism is the most popular position in philosophy of mind. Can you provide a source?

Second: It should be noted that physicalism and functionalism are not the same thing. One can be a physicalist without being a functionalist (e.g. those who subscribe to type-identity or to eliminativism). In fact John Searle accuses functionalists of being closeted dualists (see these recorded lectures on philosophy of mind by him -- I forgot which lecture number he gives the argument for why functionalists are actually dualists).

Now for the answer. In what follows, I am describing arguments against functionalism as a physicalist theory of mind (i.e. ignoring other types of physicalism besides functionalism and ignoring Searle's argument that functionalism is in fact a form of dualism):

The main argument against functionalism is that it leaves something out, namely an explanation of subjective experience. Those who oppose functionalism maintain that it is not a complete description of the mind, that it fails to account for how or why subjective experience occurs. For functionalism to be a complete description of the mind, it would have to account for subjective experience, but in fact functionalist account cannot distinguish between a conscious being on one hand, and a being who has all of the functional and behavioral features of an intelligent human but doesn't have any subjective experience such as an intelligent AI robot or a Zombie that behaves outwardly like a normal human but in fact has no conscious experience (see the SEP article on Philosophical Zombies).

Thomas Nagel describes the problem in his paper "What's it like to be a bat" (Nagel, Thomas (1974). The Philosophical Review 83 (4): 435–450.):

We may call this the subjective character of experience. It is not captured by any of the familiar, recently devised reductive analyses of the mental, for all of them are logically compatible with its absence. It is not analyzable in terms of any explanatory system of functional states, or intentional states, since these could be ascribed to robots or automata that behaved like people though they experienced nothing.

David Chalmers proposed that this is the "Hard Problem of Consciousness" (Chalmers, David (1995). "Facing Up to the Problem of Consciousness". Journal of Consciousness Studies 2 (3): 200–219.):

It is undeniable that some organisms are subjects of experience. But the question of how it is that these systems are subjects of experience is perplexing. Why is it that when our cognitive systems engage in visual and auditory information-processing, we have visual or auditory experience: the quality of deep blue, the sensation of middle C? How can we explain why there is something it is like to entertain a mental image, or to experience an emotion? It is widely agreed that experience arises from a physical basis, but we have no good explanation of why and how it so arises. Why should physical processing give rise to a rich inner life at all? It seems objectively unreasonable that it should, and yet it does.

The argument against functionalism from knowledge

In my mind the most detailed argument for why functionalism fails to explain consciousness was provided by Frank Jackson (Jackson, Frank (1986). "What Mary Didn't Know". Journal of Philosophy 83: 291–295). In his original argument, Mary is a Neuroscientist and the sensation in question is color. I will illustrate it with a variation where Mary is a Dentist and the sensation in question is tooth pain, since it is more plausible in my opinion:

  • Imagine a dentist called Mary, who is the top dentist in her field, she has aced every dentistry topic there ever was, can cure any patient who comes to her with a dental problem no matter how bad that patient's condition, and has studied every biological, neurological and chemical aspect of what a toothache is. In short she knows every single physical aspect and functional aspect of toothaches.
  • However, Mary has been an avid tooth brusher ever since she was a kid, and she has never ever had a tooth ache in her life. Most would agree that because of this, she doesn't really know what a toothache is at all, since she has never had the subjective experience of a toothache. She knows all there is to know about toothaches, but she doesn't know what a toothache is, having never had the feeling herself.
  • If Mary were to suddenly stop brushing her teeth and start eating copious amounts of chocolate, within a few months she will develop a serious toothache. The new experience she had constitutes additional knowledge of toothaches that she didn't have before she went through the subjective experience. It is argued that functionalism has no way of accounting for this additional knowledge that Mary gains from subjective experience. Functionalism incomplete, and there must a be a purely mental (or non-physical) aspect to things such as pain, color, love (i.e. qualia).

Possible functionalist responses

  • Daniel Dennett responds to this by claiming that qualia simply don't really exists in his paper "Quining Qualia" (Dennett, Daniel C., In "Consciousness in Modern Science" Anthony J. Marcel & E. Bisiach (eds.), [Book Chapter]. Oxford University Press (1988)) and later in his book "Consciousness Explained".

  • David Rosenthal, among others, proposes Higher Order Theories of consciousness to explain the existence of qualia/subjective experience within functionalism: Thoughts, beliefs, perceptions, etc..are 1st order mental (functional) states. Subjective experience are adequately described by 2nd order mental states. 2nd order functional states are functional states about other functional states.

  • 1
    As an aside, what is your personal opinion? Is there something that would be missing in principle in a computation simulating a human brain?
    – nir
    May 15, 2016 at 19:17
  • 1
    can you not come to terms with free will as a psychological illusion? I ask because I wonder why some people regard the intuition of free will so seriously. After all we are not aware of the origin of our thoughts and actions. in a way the intuition of free will is an intuition about a thing that seems to happen behind a closed door, which detracts from its force. and it is an intuition that we cannot reconcile with either determinism or randomness. finally, functionalism is compatible with compatibilist free will.
    – nir
    May 16, 2016 at 18:52
  • 1
    so, are you rejecting functionalism just because you do not like it's consequences? After all, free will is inherently about performing a function, say taking one of two actions under consideration. Is our taste, or the fact that we do not know how the decision is made, a good reason to reject the framework?
    – nir
    May 16, 2016 at 19:11
  • 1
    I admit that I am driven by preferences. But then who isn't: William James (among others) has accused Compatibilists as a whole as being driven by their tastes: They want to believe in a scientific deterministic world and that we have freewill at the same time, and so came up with a convoluted redefinition of freewill instead of simply admitting that their preferences were contradicted by the facts. May 16, 2016 at 19:17
  • 1
    what facts?....
    – nir
    May 16, 2016 at 19:18

Physicalism asks the question what the mind is made up of; what is the substance of the mind? philosophy tries to figure out what the mind looks like, if it's an actual physical object; is the mind visible? can technology detect the object we call the mind? can one Measure it? it appears that materialism was a bit vague, so the philosophers and scientists, believing in a hard materialist position, wanted to get empirical evidence of this thing called the mind.

Functionalism asked the questioned how the mind, whether physical or non-physical, not necessarily visible or not, acted. the mind has beliefs, desires, or the mind is beliefs or desires. functionalism tried to analyze the mind this way.

what if physicalism and functionalism theory of mind are legitimate in philosophy of Mind? Rather than trying to erase both studies, physicalism can elaborate the multiple views of the substance of mind to aid neuroscience into finding out what the mind looks like, functionalism can aid psychologists better understand how the mind functions; they can use functionalism to learn about peoples beliefs, desires, etc.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .