We are all human beings, and, as such, we have much in common. In particular, we are affected emotionally and in other ways by much the same things. As Shylock pointed out, ‘If you tickle us, do we not laugh? If you poison us, do we not die? And if you wrong us, shall we not revenge?’ (Merchant of Venice, Act III, Scene 1). Yet, in spite of our being members of the same species, we differ in all sorts of ways, some of them very subtle, but nevertheless very important. Humpty Dumpty, who was not a human being but an egg, said, much to Alice’s consternation, that he would not be able to recognize her again because she looked so exactly like others of her species. He complained that everybody has the two eyes in the same place, the nose in the middle, the mouth underneath. ‘It’s always the same’, he said. Whereas, he went on, if Alice had the two eyes on the same side of the nose, for instance—or the mouth at the top—that would be some help. Alice objected, however, that it wouldn’t look nice (Lewis Carroll, Through the Looking Glass, ch. VI). Whether or not Alice was right that it wouldn’t look nice, she was right that we—at least we humans if not eggs like Humpty Dumpty—are eminently capable of grasping facial differences, in spite of the fact that all our faces are human faces. This, I think, is equally true of our minds: our minds are all human, but they differ in extraordinary complex and subtle ways—ways which we have a wonderful ability to keep track of. And we need this ability. Differences in minds, like differences in faces, matter.