All posts by Julie May

Folk Psychology and Scientific Knowledge

Paul Churchland, an American philosopher, defends eliminative materialism, or that common-sense folk psychology is a theory, and must be substituted with neuroscience. In order to argue this, Churchland demonstrates how folk psychology is only a theory and why it might be false.

Churchland begins by stating that seeing folk psychology as a theory unifies problems such as “the explanation and prediction of behavior, the semantics of mental predicates, action theory, the other-minds problem, the intentionality of mental states, the nature of introspection, and the mind-body problem.” (594) In order to argue how the intentionality of mental states is a “structural feature” of folk psychology, Churchland relates to a theory in the physical sciences. He begins by giving us an example of “numerical attitudes,” or expressions such as “…has a mass of n, a velocity of n, a temperature of n.” Substituting a number for n forms a predicate in the same way that substituting a proposition for p forms a predicate. Churchland states, “The structural features of folk psychology parallel perfectly those of mathematical physcics.” (595) Although this was only a small part of his larger argument, I believe that Churchland was effective. I am personally more inclined to accept an argument that is proven valid through science and mathematics. Churchland’s thorough explanation of the parallels of folk psychology and mathematical physics make his argument obvious and clear.

Again, Churchland takes the perspective of the physical sciences when he argues why folk psychology might (really) be false. Folk psychology may only be a theory if it “fits well with other theories about adjacent subject matters.” (597) Churchland claims that folk psychology doesn’t fit in with the sciences like the theory of the homo sapiens does. Since the physical sciences are undeniable when it comes to explaining human behavior, Churchland is strong in his claim that this theory is false. Again, this seems to make sense to me. It is difficult to deny the physical sciences as it is logical in explaining many different aspects about the universe.

Churchland claims that science can explain human beings’ constitution, development and behavioral capacities through physics, chemistry, evolutionary theory, biology, physiology and neuroscience, and that using these explanations, science can beat folk psychology.

Sterelny makes a logical response to Churchland’s arguments. He says that folk psychology is an important component of cognitive psychology. Cognitive psychology includes the study of mental processes. Cognitive psychology takes part in research programs to understand processes like learning and memory. In contrast to Churchland’s scientific explanations to deny folk psychology, Sterelny says that folk psychology indirectly follows modern scientific advances. (

Thus, both Sterelny and Churchland use science to prove their argument. However, I am leaning towards Churchland’s view that folk psychology should be eliminated. Churchland makes a rational argument that neuroscience is a better way to understand the brain.

Is everything just an illusion?

According to Duncan Pritchard’s chapter about radical skepticism in “What is this thing called Knowledge?” there is no way of knowing if our brains are stimulated in a way to make our experiences seem normal. Therefore, Pritchard concludes that if we are unable to know if we are victims of skeptical hypothesis, then “we are unable to know very much at all.” (Pritchard, 170)

A modern day example of this hypothesis is demonstrated by the movie The Matrix. In the movie, a man’s brain is in a vat of nutrients and is being fed computer-induced experiences that seem to be real. Since he is being controlled in a vat, there is no way of knowing if any of his interactions are real.

An extreme example is a world that lacked physical objects except for yourself and an Evil Genius, who controls all of your experiences. In this case, your beliefs would be mistaken because “your experiences represent there to be an external world of physical objects (including tour body.)” (Brueckner) Many philosophers deny the possibility of this hypothesis because they fail to believe in a matterless world.

So, we cannot conclude that we know anything unless we are able to identify being a victim of a skeptical hypothesis, such as being in a brain vat. However, if our experiences would be indistinguishable in either case, then it is impossible to know if we are being deceived or if we are in reality.

No matter how many philosophers attempt to refute the hypothesis, it always seems to come back to the idea that we cannot distinguish an artificial experience that is designed to completely replicate a real one.

Since it is impossible to conclude that “I am not in a large vat being fed experiences that are designed to deceive me.” (Pritchard, 171) Thus, I do not know if anything that I am doing is true. Am I a college student at Emory University? Do I have the ability to type this post? Is there a book open in front of me? Or am I deceived by these appearances and experiences that seem so real? I wonder if I can be under an external power that controls my ability to experience the world.

Other Sources:

Brueckner, Tony (2004) ‘Skepticism and Content Externalism’, Stanford Encyclopedia of Philosophy