To: Frank S.
From: Geoffrey Klempner
Subject: Defending Metaphysics against Hume
Date: 9 November 2001 14:14

Dear Frank,

Thank you for your e-mail of 29 October, with your essay for units 1-3 of the Metaphysics program, 'An attempt to defend metaphysics against Hume's scepticism' and also your e-mail of 8 October.

I'll respond to the e-mail you sent today, then read your essay and respond to that.

I have spent the morning converting the archives of questions and answers on the Ask a Philosopher site into individual pages. It took me five hours to do the first six sets of questions and answers. It is quite a horrendous task, although I have now worked out a system (in fourteen steps). The result, when I have finished, will be around a thousand new web pages, each page with one question, which will be put on the new PhiloSophos.com site as a searchable philosophy knowledge base.

The reason I am telling you this is that this is quite typical of my work as an 'internet philosopher'. It is more than a full-time job. The time I get to actually think about philosophy is when I write letters to my students, or, answer questions on the 'Ask a Philosopher' site, or, occasionally, in my online notebook.

I am not typical of academic philosophers, but I imagine these days they have to work quite hard too. But the point is, as one of my philosophy students remarked, if you really love what you do then it isn't 'work'.

The Metaphysics program is the hardest of the six Pathways programs, having started initially as a course for final year undergraduates. You should take considerably more time reading the units, than you would reading a philosophy text book. Expect to read a unit three, or four times. I have set out to write an original contribution to metaphysics, rather than a mere guide to the subject.

Now, to your essay.

I like the clear way in which you have set out your argument. I am indebted to you for reminding me of the second of your two quotes from Hume where he says that we must 'cultivate true metaphysics with some care'. The point, then, is not to reject the subject metaphysics, but rather to get rid of a certain kind of bad metaphysics which as Hume characterizes it seeks to prove a priori truths which are about the world, rather than about logical relations between ideas.

Many contemporary 'metaphysicians', it should be noted would agree that metaphysics is merely a branch of philosophical analysis, dealing with 'logical relations between ideas'.

This relates to the second of your two objections to Hume. To get involved with criticizing the claims of metaphysicians is to do metaphysics. Any attempt to destroy metaphysics 'from the outside' fails to engage with the arguments of the proponents of metaphysics.

I prefer this argument to the argument that good 'metaphysics' can be defended when we see that it is just a matter of discovering logical relations between ideas, because I do think that Hume's definition of 'good metaphysics' is too restrictive. To apply that definition to Heidegger, Whitehead, or Kant or Hegel, for example, is to attempt to refute their claims 'from the outside' rather than get involved with the arguments which these philosophers put forward.

Now, on the question of causality, there are two things to say.

Hume does in fact at one point in the Treatise give 'Rules for judging causes and effects'. He does not say that there is no such thing as causation. Rather, he gives a philosophical analysis of 'A causes B' in terms of the idea of a universal law. 'All events of type A are followed by events of type B'. We can never prove such a law on the basis of our experience: this is the problem of induction. However, I do not believe that Hume is contradicting himself by talk of causal relations between ideas, because he understands 'cause' in terms of his universal law analysis.

However, there is a criticism that one can make against Hume's claim that all reasoning is merely a matter of cause and effect relations between ideas. I can cause you to change your beliefs, or I can seek to persuade you by rational means. These are two different things. Hume, in writing his Treatise, is seeking to convince the reader by rational means. If all Hume was doing was seeking to cause the reader to change their beliefs, then we would be justified in refusing to read his book - which for all that one might disagree with it is, in fact, a model of philosophical reasoning.

All the best,

Geoffrey