The Skeptics Society & Skeptic magazine

What is it like to be a Human?

by Colin McGinn

Imagine an intelligent bat contemplating the mind-body problem, name of Tim Nigel.¹ Nigel has noticed that humans have an auditory sense not possessed by bats (of his species): they can hear various pitches. This enables them to appreciate music (unlike Tim and his conspecifics) and also to have other types of auditory experience not available to bats. We can suppose that bats hear only a single pitch and only echoes of their own monotone shrieks, impressive though their sense of echolocation is. Thus Nigel concludes that he doesn’t know what it is like to be a human, at least so far as hearing is concerned. He has some inkling, to be sure, because he does have an auditory sense, but the range and variety of human hearing makes this sense alien to him—just as humans have an auditory sense that provides only partial insight into the auditory sense of bats. He thinks that if he could hear pitch variations in the manner of humans, then he would know (fully) what it is like to be human; but as things stand he cannot grasp the nature of human experience. This is a region of reality he cannot get his mind around (Nigel is a resolute metaphysical realist). He expresses his conclusion by saying that human experience is “subjective” and can only be grasped “from a particular point of view”, in contrast to “objective” things that can be grasped “from many points of view, i.e. from no specific point of view”.

Having come to this conclusion he notices an implication for the mind-body problem, namely that experiences like those of humans cannot be reduced to physical facts about the human body and brain. For such physical facts can be grasped from many points of view and don’t require that one shares the point of view of the organism having the experience. Tim can know what it is to be a human, i.e. to belong to the human biological species, but he can’t grasp what it is like to belong to the psychological type exemplified by humans, i.e. beings sensitive to pitch differences. But that means that it is not possible to analyze experiences as physical states, because the former are subjective and the latter objective. He has uncovered a feature of mental concepts that renders them incapable of analysis into physical concepts. Tim’s inability to know what it is like to be a human thus leads him to reject materialism.

The essential point of his reasoning is the contrast between concepts of experience and concepts of the physical world—the point, namely, that the former are accessible only to beings that share the experience in question while the latter are not dependent in this way. You can know what it is to be a member of the human species without yourself being of that species, but you can’t know what it is like to have human experience without having that kind of experience. And you can grasp the properties of a human brain without yourself having that kind of brain, but you can’t grasp the experiential properties with which these brain properties correlate without having those properties yourself. […]

Read the complete essay