Berkeley: Some Main Arguments

A. The Heat-Pain Argument (First Dialogue, pp. 11-14)

1. An intense heat is a pain
2. No unperceiving thing can have a pain
3. A material substance is an unperceiving thing
Therefore,
4. A material substance cannot have a pain (from 2 and 3)
Therefore,
5. A material substance cannot have an intense heat (from 1 and 4)

Hylas questions 1, but Philonous has the following argument to defend 1:

1. The fire produces the sensation of heat in me
2. The fire produces the sensation of pain in me
3. The fire produces only one sensation in me
Therefore,
4. The heat = the pain

This argument is not valid as it stands. All that can be validly inferred is that the sensation of heat = the sensation of pain. Can we fix it?

1. The fire produces the sensation of heat in me
2. The fire produces the sensation of pain in me
3. The fire produces only one sensation in me
Therefore,
4. The sensation of heat = the sensation of pain (from 1-3)
5. the pain = the sensation of pain
6. the heat = the sensation of heat
Therefore,
7. the heat = the pain

But isn't premise 6 simply false? (And thus we have no argument for premise 1 of the original argument, which also seems false)

B. Perceptual Relativity Arguments (pp. 14-15)

1. heat and cold are in material substances (assumption for reductio ad absurdum)
2. if heat and cold are in material substances, then the degree of warmth I feel is in the object
Therefore,
3. the degree of warmth I feel is in the object (from 1-2)
Therefore
4. if it feels hot, it is hot (from 3)
and
5. if it feels cold, it is cold (from 3)
6. it feels both hot and cold
Therefore,
7. it is both hot and cold

But 7 is absurd, since the same thing cannot be both hot and cold. Therefore, the initial assumption 1 is mistaken: heat and cold are not actually in material substances.

Reply: we should reject 2. Supposing that properties are in objects does not commit us to the view that the property the object appears to have is the one it really has: apparent warmth may be different from actual warmth. (For example, water that is actually lukewarm may feel hot or cold.)

C. Analogy between Heat and Pain (p. 15)

The pin pricks my finger
This causes the sensation of pain
but the pain is not in the pin

The way the pin prick causes the sensation of pain seems completely parallel to the way heat produces the sensation of pain, so by analogy we should say:

The hot coal burns my finger
this produces the sensation of heat
but the heat is not in the coal

But are these cases really parallel? There seems to be the following important difference:

pain = the sensation of pain
but
heat ≠ the sensation of heat

D. Argument from Change (pp. 21-22)

1. A property possessed by a material substance cannot change unless the object changes in some way
2. colors [or pick your favorite secondary quality] change with no change in the object
(e.g. if lighting conditions change, or the object is seen under a microscope)
Therefore
3. colors are not properties possessed by material substances

But can't we distinguish between the apparent color and the real color?

E. Argument Against "Material Substratum" (pp. 33-35)

Mostly just poking fun at Locke, who admits we don't have a positive idea of material substance. Philonous's point is that if you have no idea of material substance, then the hypothesis that there are material substances is actually meaningless.

Of course, Locke thinks that we don't have an idea of immaterial (thinking) substance either. Berkeley gets around to discussing this difficulty in the Third Dialogue, at pp. 66-67.

F. The inconceivability of an unconceived object (pp. 35-36)

Philonous: "I am content to put the whole upon this issue. If you can conceive it possible for any mixture or combination of qualities, or any sensible object whatsoever, to exist without the mind, then I will grant it actually to be so" (35).

Hylas responds: "What more easy than to conceive a tree or house existing by itself, independent of, and unperceived by, any mind whatsoever? I do at this present time conceive them existing after that manner."

Philonous points out that Hylas is conceiving the tree and house, so they are not unconceived after all.

1. If X is possible then I can conceive of X.
2. An unconceived object is possible. (Assumption for reductio ad absurdum.)
3. Let a be an unconceived object.
4. I can conceive a. (from 2, 3)
5. a is conceived. (from 4 -- ????)
Therefore,
7. An unconceived object is impossible.

Problems:

1. 5 doesn't follow from 4, so it seems that at best the argument would show that there cannot be an unconceivable object, not that there cannot be an unconceived one.

2. B slides back and forth between "conceived" and "perceived," but these are importantly different.

3. There's an important difference between conceiving of the truth of a proposition, and conceiving of an object. In particular, there's an important difference between conceiving that there is an unconceived object, and conceiving a particular unconceived object. It's true that I can't conceive a particular unconceived object, since once I conceive it, it's no longer unconceived! But it doesn't follow that I can't conceive that there is an unconceived object.

Compare: I'm sure that mathematicians in the future will prove theorems that no one now knows about. So I conceive that there are theorems I don't conceive. It doesn't follow that there is a particular theorem such that I conceive I don't conceive it!

4. B thinks that everything that is conceived is in a mind, so conclusion 7 shows that there can't be anything nonmental. But this seems question-begging, since the believer in material substance thinks that we conceive lots of things that aren't in our minds.

This is another case of a failure to distinguish between (a) representations and (b) what they represent. Whenever I conceive something, there is a representation in my mind which represents that thing. However, the fact that the representation is in my mind does not show that the thing represented is in my mind!

This is sort of the converse of what Locke does when he talks about ideas being in objects. He means that what is represented (a quality) is in the object, not that the representation is, but he frequently seems to simply not make this distinction.

Last update: March 23, 2009.
Curtis Brown  |  Classical Modern Philosophy  |  Philosophy Department  |  Trinity University
cbrown@trinity.edu