To: Max W.
From: Geoffrey Klempner
Subject: Berkeley's case against abstract ideas
Date: 25th January 2011 11:38

Dear Max,

Thank you for your email of 14 January, with your essay for the University of London Modern Philosophy: Locke, Berkeley, Hume module in response to the question, 'How successfully did Berkeley argue against abstract general ideas? Why was it important for his project to do so?'

This is a well researched essay, and a good answer to the question. However, I did find that the essay in parts read rather like a report on your reading. Lots of questions and answers are thrown up, but in the process I felt that I was losing sight of the bigger picture. I don't want to discourage this approach because you are acquiring, and displaying, the appropriate skills. However, you do need to think about how you would answer this question in an examination, where you will be thinking on your feet (which is what the examiners want to see) rather than merely trying to reproduce something you have written beforehand.

I found myself grasping for essential threads. One is the connection to the ideas of the later Wittgenstein in Philosophical Investigations and the notion that to know the meaning of a general term (or indeed any linguistic term) is to be competent in following the rules for its use. Wittgenstein takes pains to distinguish his view from nominalism in the traditional sense, or the theory that all words are just 'names'. All the work needs to be done in explaining the differences in use and function between different kinds of words -- proper names, general terms, logical connectives etc.

How exactly does this relate to Berkeley? There is a book which is relevant to this issue, a short classic 20th century text by Peter Geach called 'Mental Acts' (in the Routledge Library of Philosophy and Psychology). The target of Geach's critique is the theory which he terms 'abstractionism', an essential component in Locke's theory of abstract ideas. According to the theory of abstractionism we form concepts by noticing the similarity amongst particulars. For example, a child acquires an understanding of the term 'red' by being shown a red balloon, a red crayon, a red apple etc. As Geach convincingly argues, this puts the cart before the horse: a raft of concepts has to be acquired at the same time -- such as the notion of a 'colour', a 'surface' etc. The process of abstraction cannot explain this, whereas Wittgenstein's account of rule following can.

Even on the most generous interpretation, Berkeley doesn't offer anything like Wittgenstein's positive account of how language is mastered and used. As you say, there is a strong suspicion that some of his attacks, at least, depend on the false assumption that knowledge must be represented in an imagist way. This is in fact the main target of Wittgenstein's critique (most clearly and instructively in the opening pages of his 'Blue Book') where in order to comply with the order 'bring me a red flower', I do not need to call up an image of red in my mind, any more than I need to use a physical colour sample. To know what 'red' is, consists in being able to do things like fetching a red flower when asked to do so. This is a practical ability which not only does not require a conscious mental 'sample', but also which cannot be derived from any number of examples.

According to Wittgenstein, language learning is a matter of 'learning how to go on'. The most clearly designed signpost is useless to me if I don't know how to 'read' signposts, that is to say, if I haven't mastered the associated practical ability of going in the direction in which the signpost 'points' (what is 'pointing'? how do we learn that?).

Apart from the charge of imagism, Berkeley's particularism manifests itself as a general scepticism about any kinds of imperceptible entity, for example the entities posited by physics such as (at the time) Newtonian corpuscles. This is instrumentalism with a vengeance. But what has it got to do with abstract ideas? Nothing much, if at all. The idea of the hypothetico-deductive method is one that excited Berkeley's strong hostility. This does weaken his case somewhat. The case would be stronger if Berkeley was able to say, 'I'm not against hypothetical entities as such. The defender of abstract ideas can't claim that they are like Newtonian corpuscles. A triangle which is every conceivable size is an impossible object, tout court, as is a horse which is every conceivable build and colour etc.'

Why was it important to Berkeley to attack abstract ideas? The suggestion that this is somehow the foundation of Berkeley critique of materialism, his case for an immaterialist metaphysic, does not convince me at all. I happen to think that a strong case can be made for Berkeleian idealism, requiring a great deal of work to combat, which has nothing to do with the critique of abstractionism. (Put very briefly, the case is exactly parallel to the Australian materialists' argument against dualism, but in reverse. According to the materialist, everything we want to say about mental items and events can be expressed in terms which only refer to material entities; according to Berkeley, everything we want to say about physical items and events can be expressed in terms which only refer to mental entities: see Foster 'The Case for Idealism'.)

Undoubtedly, Berkeley saw something that Locke missed. The example of proving theorems about any triangle -- such as Pythagoras' theorem -- by drawing constructions on an arbitrarily chosen triangle is very powerful, and it is easy to see how Berkeley could have thought that somehow this was the key to understanding how general terms work. At best, he was only partly right.

All the best,

Geoffrey