someone were to say that two parts of space have a single matter, or that two hours share a single matter. Yet these are not merely distinctions among terms but among things themselves,' and they seem very apposite here, where confusing them has led to a false conclusion. These two genera share a common notion, and the notion of real genus is common to both matters; so that their genealogy will be like this: GENUS merely logical real varied by simple differentiae of which the differentiae are modifications, i.e. MATTER merely metaphysical physical involving homogeneity involving a solid homogeneous I have not seen the authorÕs second letter to the Bishop, and the prelateÕs reply to it hardly mentions the topic of thinking matter. But our authorÕs reply to this second response returns to this topic. What he says, in nearly these words,1 is this (p. 397): God adds to the essence of matter what qualities and perfections he pleases: to some parts simple motions alone, but to plants vegetation and to animals sense. Those who agree to this much immediately protest when we go one step further and say that God can give thought, reason and volition to matter, as though that destroyed the essence of matter. To prove this they urge that thought and reason are not included in the essence of matter; but that proves nothing, since motion and life are not included in it either. They also urge that we cannot conceive that matter can think; but our conception is not the measure of GodÕs power. He then cites the example of the attraction of matter on p. 399, and especially on p. 408 where he speaks of the gravitation of matter to matter, attributed to Mr Newton, in the words which I have quoted above, acknowledging that we will never be able to understand how it comes about. This amounts to a return to qualities which are occult and, what is more, inexplicable. He adds (p. 401) that nothing is more likely to favour the sceptics than denying what we do not understand, and (p. 402) that we do not even conceive how the soul thinks. He maintains (p. 403) that, since the two substances, material and immaterial, can be conceived in their bare essence, devoid of all activity, it is at GodÕs discretion to bestow the power of thought on one or the other. And he tries to take advantage of a confession by his adversary, who had conceded sense to the beasts while not allowing them any immaterial substance. He claims that liberty and self-consciousness (p. 408