One of the slogans of naturalism mentioned in the introduction is that “there is no first philosophy”. In this chapter we shall try to make sense of the idea of first philosophy – what it is and why many philosophers have thought we needed such a thing. What follows is a potted history of first philosophies – enough for us to understand both the motivations for first philosophy and to highlight some of the problems that cause naturalists to reject the very idea.

A first philosophical problem: scepticism

One philosopher proclaiming precisely that he is undertaking first philosophy is René Descartes. The full title of Descartes's most celebrated work is Meditations on First Philosophy. Descartes's aim is to rebuild our knowledge on solid foundations. He begins in a negative mode; and it is the negative aspect of Descartes's philosophy that will concern us here. He starts by questioning on what basis we can claim to know anything.

For certain cases answers readily present themselves. For example, I know that I am sitting at my desk right now with my laptop in front of me because I can see my desk, my laptop and my hands moving over the keyboard. That seems like a very good answer to the question: how do you know that you are now sitting at your desk typing on your laptop?

Descartes proceeds in the First Meditation to offer us reasons to doubt the adequacy of the simple idea that we know things about the world by looking, touching and using our other senses.