themselves are understandable without reference to their status within the wider categories under exploration by the speculative Reason — that claim is entirely unfounded. Insofar as philosophers have failed, scientists do not know what they are talking about when they pursue their own methods; and insofar as philosophers have succeeded, to that extent scientists can attain an understanding of science. With the success of philosophy, blind habits of scientific thought are transformed into analytic explanation.
The Cartesian dualism, whereby the final actualities were divided into bodies and minds, and the Newtonian materialistic cosmology, combined to set a false goal before philosophic speculation. The notion of mere bodies and of mere minds was accepted uncritically. But the ideal of explaining either minds in terms of bodies, or bodies in terms of minds guided speculative thought. First Hobbes made bodies fundamental, and reduced minds to derivative factors. Then Berkeley made minds fundamental, and reduced bodies to derivative factors — mere ideas in the minds, and more particularly in the mind of Ged. The most important effect on the relations of philosophy to natural science was, however, produced neither by Hobbes nor by Berkeley, but by Kant. The effect of his Critique of Pure Reason was to reduce the system of nature to mere appearance — or, to use the Greek word, the order of nature is phenomenal. But whether we prefer the word “appearance,” or the word
