If a dog jumps in your lap, it is because he is fond of you; but if a cat does the same thing, it is because your lap is warmer. - Alfred North Whitehead

Every intellectual revolution which has ever stirred humanity into greatness has been a passionate protest against inert ideas. Then, alas, with pathetic ignorance of human psychology, it has proceeded by some educational scheme to bind humanity afresh with inert ideas of its own fashioning.

Such a conception is paradoxical if you will persist in thinking of the actual world as a collection of passive actual substances with their private characters or qualities. In that case, it must be nonsense to ask, how one such substance can form a component in the make-up of another such substance.

There are deeper types of symbolism, in a sense artificial, and yet such that we could not get on without them. Language, written or spoken, is such a symbolism.