A Text-Book of Psychology

change by growth, and non-living objects, the objects that change only by decay. And living objects divide, again, into objects that grow in one place, the plants, and objects that move about as they grow, the animals. Here, almost at the first glance, we have distinguished the raw materials of three different sciences : geology, botany, zoology. Now let us turn to some stage of human evolution : we may choose the social life of mankind before the dawn of civilisation. Primitive man was required, by the necessities of his case, to make himself weapons ; to hunt animals for § i. Science and Experience 3 food ; to protect himself by clothing and shelter, and to avoid eating or drinking from poisonous or tainted sources. If he ventured upon the water, he must steer his course by the stars ; if he banded with his fellows, he must hold to the code of honour of the tribe. He dreamed, and told his dreams; when he was glad, or angry, or afraid, he showed his feeling in gesture or by the expression of his face. Doubtless, his daily experience, if he ever thought about it, seemed to him as chaotic as our own has just appeared to us. But we, who have a larger vision of that experience, can see that it contained the natural germs of many sciences: mechanics, zoology and physiology, — astronomy, ethics and psychology.