Until recently changes had taken place so slowly and so insensibly that only a very few persons could be expected to realize that not a few of the beliefs that were accepted as eternal verities were due to the inevitable misunderstandings of a savage. In speaking of the "savage" or "primitive mind", we are, of course, using a very clumsy expression. We shall employ the term, nevertheless, to indicate the characteristics of the human mind when there was as yet no writing, no organized industry or mechanical arts, no money, no important specialization of function except between the sexes, no settled life in large communities. The period so described covers all but about five or six thousand of the half million to a million years that man has existed on the earth. There are no chronicles to tell us the story of those long centuries. Some inferences can be made from the increasing artfulness and variety of the flint weapons and tools which we find. But the stone weapons which have come down to us, even in their crudest forms (eoliths), are very far from representing the earliest achievements of man in the accumulation of culture. Those dim, remote cycles must have been full of great, but inconspicuous, originators who laid the foundations of civilization in discoveries and achievements so long taken for granted that we do not realize that they ever had to be made at all. Since man is descended from less highly endowed animals, there must have been a time when the man-animal was in a state of animal ignorance. He started with no more than an ape is able to know. He had to learn everything for himself, as he had no one to teach him the tricks that apes and children can be taught by sophisticated human beings. He was necessarily self-taught, and began, as we have seen, in a state of ignorance beyond anything we can readily conceive. He lived naked and speechless in the woods, or wandered over the plains without artificial shelter or any way of cooking his food. He subsisted on raw fruit, berries, roots, insects, and such animals as he could strike down or pick up dead. His mind must have corresponded with his brutish state. He must at the first have learned just as his animal relatives learn--by fumbling and by forming accidental associations. He had impulses and such sagacity as he individually derived from experience, but no heritage of knowledge accumulated by the group and transmitted by education. This heritage had to be constructed on man's potentialities.