To return, however, to terra firma. I believe I am right in saying that the essence of language lies in the intentional conveyance of ideas from one living being to another through the instrumentality of arbitrary tokens or symbols agreed upon and understood by both as being associated with the particular ideas in question. The nature of the symbol chosen is a matter of indifference; it may be anything that appeals to human senses, and is not too hot or too heavy; the essence of the matter lies in a mutual covenant that whatever it is shall stand invariably for the same thing, or nearly so.
We shall see this more easily if we observe the differences between written and spoken language. The written word “stone,” and the spoken word, are each of them symbols arrived at in the first instance arbitrarily. They are neither of them more like the other than they are to the idea of a stone which rises before our minds, when we either see or hear the word, or than this idea again is like the actual stone itself, but nevertheless the spoken symbol and the written one each alike convey with certainty the combination of ideas to which we have agreed to attach them.
The written symbol is formed with the hand, appeals to the eye, leaves a material trace as long as paper and ink last, can travel as far as paper and ink can travel, and can be imprinted on eye after eye practically ad infinitum both as regards time and space.
The spoken symbol is formed by means of various organs in or about the mouth, appeals to the ear, not the eye, perishes instantly without material trace, and if it lives at all does so only in the minds of those who heard it. The range of its action is no wider than that within which a voice can be heard; and every time a fresh impression is wanted the type must be set up anew.