Language is the communication that more obviously than anything else, that distinguishes humankind from the rest of the animal world. Humans have also been described as tool-making animals; but language itself is the most remarkable tool that they have invented, and is the one that makes most of the other possible. The most primitive tools, admittedly, may have come earlier than language: the higher apes sometimes use sticks as elementary tools, and even break them for this purpose. But tools of any greater sophistication demand the kind of human co-operation and division of labour which is hardly possible without language. Language, in fact is the great machine tool which makes human culture possible.