But there is no doubt that my own views on this are, in quite a number of ways, very different from those of Quine.

Here, as in so many other cases, however, it turns out that a very commonsensical idea looks far less attractive when one examines some of the experimental work which is not available to us from the armchair.

There is a worry that many have expressed that, on the naturalistic way of approaching philosophical questions, philosophy will somehow be co-opted by science. I'm not much worried about this.

No one would suggest that we can adequately investigate what makes something an acid, or what makes something aluminum, by bringing our pretheoretical intuitions about these things into reflective equilibrium by way of armchair theorising.

No one worries terribly much about who the questions belong to, or whether a given contribution is really philosophy or, instead, properly nothing but science. Perhaps another way to put this is that, although I think that knowledge is a natural kind, I don't think that philosophy is.

In my view, philosophers have shown a great deal more respect for the first-person point of view than it deserves. There's a lot of empirical work on the various psychological mechanisms by way of which the first-person point of view is produced, and, when we understand this, I believe, we can stop romanticising and mythologising the first-person perspective.

I have made some headway in addressing these questions, however, and succeeded in explaining how it is that the category of knowledge might play an important role in empirical theories. To the extent that talk of knowledge can be shown to play an explanatory role in such theories, the analogy I wish to make with paradigm natural kinds such as acids and aluminum starts to make a good deal of sense. This is, of course, connected with the issue of the role of intuitions in philosophy.