30 January 1998
Thank you for your comments on unit 11 of The Possible World Machine. I can't criticise you for joining the hordes who derided Berkeley's theory when it first appeared. If one's only concern is with what is or with what has at least a fair chance of being a true account of reality, then one may need a lot of convincing that Berkeley ought to be taken seriously. Fairly recently a philosopher from Liverpool University, Barry Dainton, gave a paper at our Departmental Seminar defending idealism. There was I'm afraid to say quite a lot of sniggering in the corridors afterwards. (It is fair to point out that Dainton did not do his cause a lot of good by setting out his paper as an exposition of the arguments of another philosopher, John Foster in his virtually unreadable book The Case for Idealism, Routledge.)
Though I am not persuaded to believe it, I find Berkeley's vision of our perception of the external world as the perception of the inside of God's mind a fascinating and powerful one. More than that, however, apart from Berkeley there is an entire philosophical tradition including Leibniz, Kant, Schopenhauer and Hegel that has taken the arguments for idealism seriously. Berkeley's is the simplest, perhaps the most simplistic version of idealism. But you should look at those other philosophers before passing summary judgement.
Getting back to Berkeley, you have a good point (and not just a gut reaction) in the observation about his intense opposition to Locke. In his Essay, Locke oscillates between the notion of substance as the subject matter of physics (atoms or 'corpuscles' or whatever the ontology of our current physical theory is held to contain) and the notion of substance as an unknowable 'something' perpetually hidden behind the veil of an object's sensible properties. Berkeley is suspicious of both these notions of substance. The first suspicion effectively a suspicion about the notion of hypothetico-deductive explanation would now be judged unfounded by philosophers of science. The second suspicion, by contrast, is extremely well founded. The only trouble is that rejecting the idea of substance as an 'I know not what' does not get you to Berkeleian idealism.
The core of Berkeley's vision may be found in his reaction to Descartes. Descartes hypothesised that my experience would be just as it is now if it was caused by an evil demon, and not by my perception of 'real' objects in 'real' space. If you buy that simply as a hypothetical possibility no matter how far fetched then you have to answer Berkeley's question: what difference would it make? Forget about God. Let's just talk about 'the source of our experience of an external world whatever that is'. You say experience must have an ultimate source and Berkeley agrees. The question is whether we have any right to say any more than that, given that the world of our experience is all we shall ever, or can ever know. If Berkeley goes further than he should in calling the ultimate source 'God' then so do we in calling it 'matter'. Or, at least, so says the transcendental idealist.
About the stone kicking incident, I did get the story wrong in one fairly significant detail. Reading Boswell's account (as reproduced in an article in the Oxford Companion to Philosophy), it turns out that Dr Johnson kicked a very large stone with so much force that his foot rebounded, leaving the stone exactly where it was. In my story, I had Dr Johnson kick the stone across the yard. The true account is actually the better one! Matter is what resists our physical action, brings us to a halt. It is because we are agents and not passive observers that idealism is impossible to believe (at least, so the argument would go).
Regarding the Dawkins/ Gould controversy, I'm afraid I have not had the opportunity to read anything by Gould. I'll keep my eyes peeled, though.