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Notes for a talk, made available by permission of Cheryl Chen

Perceptual Experience and Bodily Action

Cheryl Chen
Bryn Mawr College
Notes for a Philosophy Seminar
September 29, 2004

The recent trend: to show that perceptual experience depends on bodily action

My view: bodily action depends on perceptual experience

The case of two gods: bodily action without perceptual experience?

Consider the case of the two gods. They inhabit a certain possible world, and they know exactly which world it is. Therefore they know every proposition that is true at their world. Insofar as knowledge is a propositional attitude, they are omniscient. Still I can imagine them to suffer ignorance: neither one knows which of the two he is. They are not exactly alike. One lives on top of the tallest mountain and throws down manna; the other lives on top of the coldest mountain and throws down thunderbolts. Neither one knows whether he lives on the tallest mountain or on the coldest mountain; nor whether he throws manna or thunderbolts. (David Lewis, "Attitudes De Dicto and De Se")

I think that the story of the two gods does not make sense in the end.

What the two gods lack: points of view and egocentric beliefs

The two gods fail to have a point of view. Having a point of view requires more than just having beliefs about how things are in the world. You need to have beliefs about how things are in relation to you.

Perry’s supermarket example:

I once followed a trail of sugar on a supermarket floor, pushing my trolly down the aisle on one side of a tall counter and back along the aisle on the other, seeking the shopper with the torn bag to tell him he was making a mess. With each trip around the counter, the trail became thicker. But I seemed unable to catch up. Finally, it dawned on me. I was the shopper I was trying to catch.

I believed at the outset that the shopper with a torn bag was making a mess. And I was right. But I did not believe that I was making a mess. That seems to be something I came to believe. And when I came to believe that, I stopped following the trail around the counter, and rearranged the town bag in my trolley. My change in beliefs seems to explain my change in behavior. (John Perry, "The Problem of the Essential Indexical")

Perry’s example brings out the difference between believing:

  1. Someone is making a mess
  2. I am making a mess

Egocentric beliefs:

Egocentric beliefs are required for bodily action:

How perception gives us egocentric beliefs: immunity to error through misidentification

The self-identification requirement: You can’t have any egocentric beliefs unless you have identified a particular person in the world as yourself. (Or to put it another way: unless you have identified a particular body as your own.)

Immunity to error through misidentification:

There are two different cases in the use of the word ‘I’ (or ‘my’) which I might call ‘the use as object’ and ‘the use as subject’. Examples of the first kind of use are these: ‘My arm is broken’, ‘I have grown six inches’, ‘I have a bump on my forehead’, ‘The wind is blowing my hair about’. Examples of the second kind are: ‘I see so and so’, ‘I hear so and so’, ‘I try to lift my arm’, ‘I think it will rain’, ‘I have a toothache’. One can point to the difference between these two categories by saying: The cases of the first category involve the recognition of a particular person, and there is in these cases the possibility of error, or as I should rather put it: The possibility of an error has been provided for…It is possible that, say in an accident, I should feel a pain in my arm, see a broken arm at my side, and think it is mine, when really it is my neighbour’s. And I could, looking into a mirror, mistake a bump on his forehead for one on mine. On the other hand there is no question of recognizing a person when I say I have a toothache. To ask ‘are you sure that it’s you who have pains?’ would be nonsensical…And now this way of stating our idea suggests itself: that it is impossible that in making the statement ‘I have a toothache’ I should have mistaken another person for myself…(Wittgenstein, The Blue and Brown Books)

Consider the following sentences:

  1. Someone is at the door, but is it the postman at the door?
  2. Someone is making a mess, but is it me who is making a mess?
  3. Someone is in pain, but is it me who is in pain?
  4. There’s a piece of paper in front of someone, but is it in front of me?

(1) and (2) are not immune to error through misidentification.

(3) is immune to error through misidentification because the way I know that someone is in pain is by knowing that I am in pain.

(4) is immune to error through misidentification if I come to believe there is a piece of paper in front of me through perception–by seeing the piece of paper before me. In that case, the way in which I come to believe that there’s a piece of paper in front of someone is by coming to believe it is in front of me.

Conclusion: self-identification is not a problem for perceivers because there is no room here for mis-identification.

Why self-identification is impossible without perception: the case of Wanda

Wanda has beliefs but no perceptual experiences.

Some of Wanda’s beliefs:

Bryn Mawr College is in Pennsylvania.
The Red Sox won against Tampa Bay last night.
Donald Rumsfeld is the Secretary of Defense.
Someone is running up the steps of the Phila. Art Museum.
Someone is walking a dog in Fairmount Park

Is Wanda capable of believing, for example, that she is the person who is running up the steps of the Philadelphia Art Museum? (My view: no)

Some facts about how we are generally related to our own bodies.

These facts suggest that our conception of body-ownership is connected with perception and action. But Wanda cannot make use of any connection between body-ownership and perception. Instead, if Wanda has any conception of body-ownership at all, it seems that it should be linked in some way with action: or, more specifically, with bodily-control.

Since we have proprioception, we do not control our bodies the way a pilot controls a ship:

We do not turn, as it were, an inner wheel in order, through some elaborate transmission of impulse, to cause an external rudder to shift, and in so doing, get our boat to turn. (Arthur Danto)

But Wanda cannot feel herself exert control over her body, so she would be like a pilot in a ship. If Wanda could believe that she has control over a particular body, it could only amount to a belief that there are correlations between particular kinds of "volitions" or "acts of will" and various bodily movements.

Volition to move left arm -> Left arm on body moves
Volition to move right leg -> Right leg on body moves

Problem: Without proprioception, Wanda has no way of distinguishing between different volitions.

Conclusion: Wanda is incapable of believing that she has control over a body, and therefore cannot satisfy the self-identification requirement. So Wanda cannot have any egocentric beliefs nor perform any bodily actions. She is no better off than the two gods.

No perception
No self-identification
No egocentric beliefs
No intentional action

See on-line forum for continuing discussion/comments

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