Tuesday 3/6

Tuesday 3/6

Robot Intentionality VI: Externalism and Distributed Cognition

Readings

Texts

Synopsis

At the crudest level of explanation, intentionality is the relation of X to Y whereby X is about Y. Thus the sentence

The cat is on the mat.

is about

The state of affairs of the cat's being on the mat.

whether the cat happens to be on the mat or not. That is, the sentence is about the the state of affairs it describes. Crudely, it is true if the state of affairs it describes obtains and false otherwise.

Yet the sentence, understood as a mere inscription--or, in this case, a particular arrangement of pixels--has at most derived intentionality. It is about nothing, it describes nothing, absent some English-user's interpretation. Thus the sentence 'means' what it means provided it can be taken to have that meaning. The sentence's (derived) intentionality presupposes the English-user's (original) intentionality. Put another way, the sentence has the meaning it has only to the extent that it is understood to have that meaning. Yet understanding is presumably a psychological state. Apparently, then, original intentionality is a special relation between psychological states and the states of affairs they are about.

Surely, then, the nature of my psychological states should determine what they are about. My thoughts are about the world, but they are first and foremost my thoughts.

A problem with this view emerges when we consider linguistic communication.

Let us suppose, as seems natural, that knowing the meaning of a term is to be in some particular psychological state with respect to the term.

Let us further suppose that the meaning of a term determines its reference, as again seems natural.

Then under the physicalist assumption that there cannot be a difference in psychological state without a difference in physical state, we conclude that, in using a term, there cannot be a difference in reference without a difference in physical state.

Following Putnam, though, we find that "water" as I use it on Earth differs in reference from "water" as my Twin-Earth counterpart uses it, even though I and my Twin-Earth counterpart are micro-physical duplicates. Hence there can be a difference in reference without a difference in physical state. What my psychological states are about seems to have nothing to do with my psychological states per se. Meanings, as Putnam memorably puts it, "ain't in the head!"

This is an admittedly condensed way of putting the problem. Suffice it to say that the problem of intentionality inherits results from the philosophy of language (a fact which should be obvious when we reflect on what we mean by "intentionality"), and those results are not always happy for the philosophy of mind.

Pursuing externalism further, we begin to wonder where the mind starts and stops. A convenient place to draw the line at mind is at the skin: Our minds go no further than our bodies. An intriguing hypothesis is that the mind does not so sharply coincide with the body. Rather, cognitive processes extend beyond the body to encompass, for example, communication and information technologies.

Unfortunately, our investigation of intentionality must stop at this bewildering possibility. It turns out there are a number of further challenges to the possibility of understanding the mind vis-a-vis Dretske's Dictum, and we must make room for them.

Next time we turn to the hard problem of consciousness, which has been justly called the most difficult problem facing science today.