Fa. A horse then, is a quadruped: by this we distinguish him from birds, fishes, and insects.
Ch. And from men.
Fa. True; but if you had been talking about birds, you would not have found it so easy to distinguish them.
Ch. How so? a man is not at all like a bird.
Fa. Yet an ancient philosopher could find no way to distinguish them, but by calling man a two-legged animal without feathers.
Ch. I think he was very silly; they are not at all alike, though they have both two legs.
Fa. Another ancient philosopher, called Diogenes, was of your opinion. He stripped a cock of his feathers, and turned him into the school where Plato, that was his name, was teaching, and said, “Here is Plato’s man for you!”
Ch. I wish I had been there, I should have laughed very much.
Fa. Probably. Before we laugh at others, however, let us see what we can do ourselves. We have not yet found anything which will distinguish a horse from an elephant, or from a Norway rat.
Ch. Oh, that is easy enough! An elephant is very large, and a rat is very small; a horse is neither large nor small.