What is it like to be a bat?

In my blog last week I defended the view that Frank Jackson’s article “What Mary Didn’t Know” doesn’t reject the thesis that the world is entirely physical, as it pretends. At most the article shows that there are two types of knowledge: physical knowledge, which describes the world in a physical way, and experiential or phenomenal knowledge, which says how we experience the world. But it is quite well possible that our experiences have a physical foundation. Can’t we say more about how the world is constituted?

One thesis that says that the physical is not all there is, is John Searle’s “Chinese Room argument” (https://en.wikipedia.org/wiki/Chinese_room). However, here I want to discuss another famous contribution to the debate: Thomas Nagel’s “What is it like to be a bat?”. This article was first published in 1974 and is about the mind-body problem. I will talk here only about the first part of the article, which leads to a conclusion which is relevant for my question how the world is constituted.

Conscious experience is a widespread phenomenon that we cannot ignore, so Nagel. It occurs not only in man but at many levels of animal life. Although it exists in several forms, the essence is “the fact that an organism has conscious experience at all means, basically, that there is something it is like to be that organism.” And “[A]n organism has conscious mental states if and only if there is something that it is to be that organism – something it is like for the organism.” (166). Nagel calls this “the subjective character of experience” (166) and says that this cannot be reduced to functional or intentional states. Robots and automata can have such states, and men can have them, too, but unlike men robots and automata experience nothing. (167) Now the question is: Does subjective experience, or at least its phenomenal features, have a physical basis? Nagel’s reply here is: “If physicalism is to be defended, the phenomenological features must themselves be given a physical account. But when we examine their subjective character it seems that such a result is impossible. The reason is that every subjective phenomenon is essentially connected with a single point of view, and it seems inevitable that an objective, physical theory will abandon that point of view.” (167)

In order to make clear that there is “a connexion between subjectivity and a point of view” and that there are “two types of conception, subjective and objective” (168) Nagel presents his famous bat example. Bats are in many respects like us, but they have a way of life and a sensory apparatus (a kind of echolocation) that is so different from the human way of life and set-up that it is a problem for man to imagine and experience what it is like to be so. Man can imagine and experience a lot and “[t]he subjective character of the experience of a person deaf and blind from birth is not accessible to me, for example, nor presumably is mine to him. [Nevertheless, t]his does not prevent us each from believing that the other’s experience has such a subjective character.” (170) And so we can imagine and experience in a certain sense what it is like to be deaf and blind from birth, but what is it like to be a bat? In more than three pages in his article Nagel explains that this seems to be impossible. (168-171) Therefore, “[r]eflection on what it is like to be a bat seems to lead us ... to the conclusion that there are facts that do not consist in the truth of propositions expressible in a human language. We can be compelled to recognize the existence of such facts without being able to state or comprehend them.”(171; my italics) This then brings Nagel to “a general observation about the subjective character of experience. Whatever may be the status of facts about what it is like to be a human being, or a bat, or a Martian, these appear to be facts that embody a particular point of view.” (171)

Let’s return to the beginning of this blog. There I stated that there are – at least – two kinds of knowledge: physical knowledge and phenomenal knowledge. Following Nagel we see that there are also two kinds of facts: physical facts and phenomenal facts. We can also say: objective and subjective facts. Physical knowledge is about physical facts; phenomenal knowledge is about phenomenal facts.

I assume that I don’t need to explain what physical facts are. Yet a few words about phenomenal facts. It looks as if they are purely personal, in the sense that they count only for you or only for me. That’s not the case. As Nagel explains: “The point of view in question is not one accessible only to a single individual. Rather it is a type. It is often possible to take up a point of view other than one’s own ... There is a sense in which phenomenological facts are perfectly objective: one person can know or say of another what the quality of the other's experience is. They are subjective, however, in the sense that even this objective ascription of experience is possible only for someone sufficiently similar to the object of ascription to be able to adopt his point of view...” (171-2; my italics)

Wittgenstein famously said “The world is the totality of facts” (Tractatus 1.1). We have now seen that there are physical facts and phenomenal facts, but, alas, we don’t know how these facts are constituted.

Source

Thomas Nagel, “What is it like to be a bat?”, in Mortal questions. Cambridge: Cambridge University Press, 1991; pp. 165-180.