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.