Are we surprised at the want of surprise on the part of the cow? Why should we be? What knows she of anatomy or of physiology? If she could think at all about the matter, she would, no doubt, have expected her calf to be composed of condensed milk. But failing that, why not hay? She had presumably some little experience of _putting_ hay inside. Why not _find_ hay inside; and, finding hay, why not enjoy the good provender thus provided? But clearly we must not expect the brutes to possess knowledge to which they cannot attain about matters which in no wise concern their daily life. "In our estimates of the characters of animals," continues Mr. Hamerton, in his comments on this anecdote, "we always commit one of two mistakes--either we conclude that the beasts have great knowledge because they are so clever, or else we fancy that they must be stupid because they are so ignorant." "The main difficulty in conceiving the mental states of animals," says the same observer, "is that the moment we think of them as _human_, we are lost." Yes, but the pity of it is that we cannot think of them in any other terms than those of human consciousness. The only world of constructs that we know is the world constructed by man. "To Newton and to Newton's dog, Diamond," said Carlyle, "what a different pair of universes! while the painting in the optical retina of both was most likely the same." Different, indeed; if we can be permitted, without extravagance, to speak of the universe as existing at all for Diamond, or allowed, except in hyperbole, to set side by side a conception of ultimate generality, like the universe, the summation of all conceptions, and "the painting in the optical retina." Carlyle's meaning is, however, clear enough. Given two different minds and the same facts, how different are the products! In the construct formed on sight of the simplest object, we give far more than we receive; and what we give is a special resultant of inheritance and individual acquisition. No two of us give quite the same in amount or in quality. It is not too much to say that for no two human beings is the world we live in quite the same. And if this be so of human-folk, how different must be the world of man from the world of the dog--the world of Newton from the world of Diamond!