People who subscribe to the idea of functionalism argue that the mind and the body can be compared to a computer and a robot. They continue that the mind is similar to a computer in a robot in that the mind is just the processing unit of the body. Furthermore, they argue that given the same causal objects, the mind can interpret the stimuli generated thereof similarly despite the characteristics of the person. It is to say that robots can also feel the same emotions and interpret stimuli the same way as humans in spite of the fact that they are made of metals and silicon (Harman 32).
In The Intrinsic Quality of Experience, Harman evaluates three objections to functionalism. The first argument is that people are aware of the intrinsic features of the experience. The author states that there is no way to account for it in functionalism (Harman 31). The second objection argues that a person who has been blind since birth can know all about the functional role of visual experience without having the knowledge of what it is like to see something red. The third and final argument is that functionalism does not account for an inverted spectrum. Of all the three arguments, the third argument appeals to be the strongest because of the reasons discussed in the next paragraph.
The objection states that it is conceivable that two people can have the same visual functioning system, but still see one thing in two different perspectives (Harman 46). For example, while one sees a thing as red, the other can see the same thing as orange. Moreover, what one person sees as orange, the other can see as yellow. It is what is called an inverted spectrum. This idea alone disqualifies functionalism. In functionalism, the argument is that the brain interprets stimuli from an external object irrespective of the person in the same way two computers fed with the same input data would give the same output despite the different materials from which they were made or the difference in the makes of the machines. The third argument proves that it is false. It is actually possible for two people looking at the same thing to perceive it differently. It shows that the relationship between the mind and the body is not entirely parallel. Rather, the former reads and interprets stimuli dependent to the latter. It also shows that there is a very important aspect of a person’s mental life that the functionalism fails to capture, making it false.
In Harman’s reaction to this objection, he uses an example of two people, Alice and Fred, and a strawberry as their common object of interest (47). The only difference is that the woman says the strawberry is red, while the man sees a different color, but thinks it is red. Harman (47) argues that if the hypothesis is to hold water, then it means that what Fred and Alice have are two different belief systems. It is derived from the fact that if there can be no distinction between what an object looks like in its natural form from how two people perceive it if at all their visual systems are normal (Harman 48). If one argues that they have the same belief of what is color red, then it means they have different visual perception systems which insinuate that one of them is not functioning in the normal way.
Harman makes a strong case when evaluating the inverted spectrum. If two people view the same thing differently, then it means the visual perception system for one of them is not functioning normally. However, the inverted spectrum demands that the visual perception in both should be normal. Therefore, it only means that their belief systems must be different.
Harman, Gilbert. “The Intrinsic Quality of Experience.” Philosophical Perspectives, vol. 4, 1990, pp. 31-52.