We have already seen that it is in virtue of such an understood covenant that symbols so unlike one another as the written word "stone" and the spoken word alike at once raise the idea of a stone in our minds. See how the same holds good as regards the different languages that pass current in different nations. The letters p, i, e, r, r, e convey the idea of a stone to a Frenchman as readily as s, t, o, n, e do to ourselves. And why? because that is the covenant that has been struck between those who speak and those who are spoken to. Our "stone" conveys no idea to a Frenchman, nor his "pierre" to us, unless we have done what is commonly called acquiring one another's language. To acquire a foreign language is only to learn and adhere to the covenants in respect of symbols which the nation in question has adopted and adheres to. Till we have done this we neither of us know the rules, so to speak, of the game that the other is playing, and cannot, therefore, play together; but the convention being once known and consented to, it does not matter whether we raise the idea of a stone by the words "lapis," or by "lithos," "pietra," "pierre," "stein," "stane" or "stone"; we may choose what symbols written or spoken we choose, and one set, unless they are of unwieldy length, will do as well as another, if we can get other people to choose the same and stick to them; it is the accepting and sticking to them that matters, not the symbols. The whole power of spoken language is vested in the invariableness with which certain symbols are associated with certain ideas. If we are strict in always connecting the same symbols with the same ideas, we speak well, keep our meaning clear to ourselves, and convey it readily and accurately to anyone who is also fairly strict. If, on the other hand, we use the same combination of symbols for one thing one day and for another the next, we abuse our symbols instead of using them, and those who indulge in slovenly habits in this respect ere long lose the power alike of thinking and of expressing themselves correctly. The symbols, however, in the first instance, may be anything in the wide world that we have a fancy for. They have no more to do with the ideas they serve to convey than money has with the things that it serves to buy.