The necessity of learning the whole art of hunting from its rudiments, without the help of instinct or tradition, by sheer observation, memory and inference, put extraordinary stress upon the brain. At first by knowledge, strategy, co-operation and persistence of will, later by devising weapons and snares, evolving language and discovering the ways of making and utilising fire, man found means of entirely changing the conditions of his life; but this would have been impossible without a great development of his brain; and, accordingly, it appears that Eoanthropus, at the beginning of the Pleistocene, had a skull with three times the cubic capacity of the anthropoids. With the growth of the brain came a continually increasing fecundity of ideas. “Piltdown man saw, heard, felt, thought, and dreamt much as we do.”[82] The use of ideas is to foresee events and prepare for them beforehand: the great advantage of distance-senses over contact-senses, is to give an animal time to adapt its actions to deferred events; and ideas give this power in a vastly higher degree. So far the utility of brains and ideas seems obvious. But in order that ideas may be useful in this way, they must (one would suppose) represent and anticipate the actual course of events. If they falsely indicate the order of nature, or even beings and actions that do not exist at all, ideas may seem to be worse than useless. Now, when we turn to the lowest existing savages, they are found to possess, in comparison with apes, a considerable fecundity of ideas; constituting, on the one hand, a good stock of common sense, or knowledge of the properties and activities of the things and animals around them, and of how to deal with them, which enables them to carry on the affairs of a life much more complex and continuous than any animal’s: but including, on the other hand, a strange collection of beliefs about magic and spirits, which entirely misrepresent the course of nature and the effective population of the world. These latter beliefs, or imaginative delusions, hamper them in so many ways, waste so much time, lead them sometimes into such dark and cruel practices, that one may be excused for wondering whether their bigger brains can have been, on the whole, of any biological advantage to them in comparison with the anthropoids. The anthropoids live by common sense. So do savages, and they have much more of it; but the anthropoids seem not to be troubled by magic and animism. We must suppose that the common sense of primitive man increased age by age, as he became more and more perfectly adapted to the hunting-life, and that at some stage his imagination began to falsify the relations of things and the powers of nature. It seems that imagination-beliefs depend chiefly upon the influence of desire and fear, suggestibility, hasty generalisation, and the seduction of reasoning by analogy. At what stage imaginations, thus