What, then, is the primary difference between written words that _are_ literature and written words that are _not_? The primary difference relates to the objects at which severally the writers aim or the motive by which they are impelled to write. The child writes solely because literary composition is a pleasure to him, as for the sake of a similar pleasure another child takes to a piano. The astronomer and the doctor write to help men in navigating ships or mothers in dosing babies. Between written language which is not literature and written language which _is_ the initial difference is this: that for the writers written language is, in the first case, something which it is not in the second. In the first case, the writer's concern with language, and the sole interest which written language has for him, are things which have no dependence on the merits of written language as such, except in so far as it is a means of accomplishing ulterior objects, with which otherwise the mere merits of language have nothing at all to do. Sound injunctions to a nurse, provided that their meaning was clear, would have far greater value in a hospital than mistaken injunctions written with a grace or majesty worthy of Plato or Tacitus. In the second case, writing is a feat the successful achievement of which is, for the writer, an object and a pleasure in itself; and how far success is achieved by him depends not alone on the pleasure which he derives from his own performances personally, but also, and we may say mainly, on the quantity of kindred pleasure which his writing communicates to his readers.