To: Max T.
From: Geoffrey Klempner
Subject: Berkeley's arguments against the existence of material objects
Date: 3 December 2003 16:33

Dear Max,

Thank you for your-mail of 16 November, with your fourth essay for the Metaphysics program, in response to the question, 'Critically discuss Bishop Berkeley's arguments against the existence of material objects.'

I have great respect for Anthony Grayling, although I have not seen his book 'Berkeley The Central Arguments'. So I don't know how heavily your account relies on Grayling's exposition. My immediate impression is that the two arguments which you select do not do Berkeley full justice. However, it is very easy to succumb to the temptation to put arguments into Berkeley's mouth which he did not succeed in putting down on paper. It is possible that I have done this in my account of Berkeley's immaterialism. In my defence, I believe that Berkeley did have very good reasons for attacking the idea of 'matter', even though I do not agree with his conclusions.

You don't attempt to say what you think is wrong with the two arguments you have given (call them 'argument A' and 'argument B') other than to comment at the end of the essay that 'One could just as easily accept the truth of proposition 0 and reject at least one of propositions 1-5'. But how easy is this, actually?

One possible target for attack in argument A is step 2. 'Perceived objects are ideas or sensations.' The obvious objection is that there is a world of difference between a sensation, like a sensation of pain, or a red after-image, or ringing in the ears, and an object like this table. But we know what Berkeley's response to this objection is going to be. Point out any part or aspect of the table. What you are pointing to is just something you experience, your impression. Add these up and all you have is a collection of 'ideas'

Berkeley is relying here on Descartes' argument in Meditation 1, that nothing in our experience tells us that there are such things as space-occupying objects. According to Descartes, nothing is in fact taken away from our actual experience when we remove physical space and matter. But then how, on the basis of our experience, can we so much as formulate the concept (the 'idea') of physical space or matter?

I notice that in argument B you inadvertently miss out the word 'like' in the sentence, 'an idea can be *like* nothing but another idea' (Principles, section 9). Here, Berkeley casts scorn on one attempt to formulate the concept of matter, based on the thought that our concept of matter is a 'pattern or image' of matter in itself. That's nonsense, he says, because 'an idea can be [a pattern or image of] nothing but another idea'.

Apart from arguments A and B, you give two apparently very different ways in which Berkeley attempts to explain how objects can exist unperceived. On the first view, my statement about a physical object which I do not currently perceive is just a conditional statement about possible sense impressions. On the second view, my statement is not a conditional statement but a categorical statement about an object which exists in God's mind.

But how are these two views connected? Berkeley evidently felt that there had to be a non-conditional fact which made these conditional statements true, just as the statement 'If this match is struck it will light' is made true by non-conditional facts about the matches chemical constitution.

I'm not sure I got the point of your question, 'Can the idea of warmth exist in a plant, animal or robot?' Possibly, you were unconsciously thinking of Leibniz, whose 'monads' are subjects of their own more or less 'confused' perceptions, and only in virtue of that are they capable of being objects of perception.

You are quite right that Berkeley's strong empiricism is on the face of it inconsistent with Platonism/ realism about numbers. One might think that, since ultimately all things exist in the mind of God, there is surely space in God's mind for numbers too. That is not a satisfactory answer for Berkeley, because he still has to account for human *knowledge* of arithmetic.

All the best,

Geoffrey