The primary needs of man which he shares with the other animals are an atmosphere which he can breathe, a temperature which he can support, water which he can drink, and food. In respect of these he is as much the product of geographical conditions as are the other living creatures. Presently he superadds another need, that of clothing. It is a sign that he is becoming less dependent on external conditions, for by means of clothing he can make his own temperature and succeed in enduring a degree of cold, or changes from heat to cold, which might otherwise shorten his life. The discovery of fire carries him a long step further, for it not only puts him less at the mercy of low temperatures, but extends the range of his food supplies, and enables him, by procuring better tools and weapons, to obtain his food more easily. We need not pursue his upward course, at every stage of which he finds himself better and still better able to escape from the thraldom of Nature, and to turn to account the forces which she puts at his disposal. But although he becomes more and more independent, more and more master not only of himself, but of her, he is none the less always for many purposes the creature of the conditions with which she surrounds him. He always needs what she gives him. He must always have regard to the laws which he finds operating through her realm. He always finds it the easiest course to obey, and to use rather than to attempt to resist her. Here let me pause to notice a remarkable contrast between the earlier and the later stages of man’s relations to Nature. In the earlier stages he lies helpless before her, and must take what she chooses to bestow--food, shelter, materials for clothing, means of defence against the wild beasts, who are in strength far more than a match for him. He depends upon her from necessity, and is better or worse off according as she is more or less generous. [Sidenote: Man’s Advance in Knowledge] But in the later stages of his progress he has, by accumulating a store of knowledge, and by the development of his intelligence, energy, and self-confidence, raised himself out of his old difficulties. He no longer dreads the wild beasts. They, or such of them as remain, begin to dread him, for he is crafty, and can kill them at a distance. He erects dwellings which can withstand rain and tempest. He irrigates hitherto barren lands and raises abundant crops from them. When he has invented machinery, he produces in an hour clothing better than his hands could formerly have produced in a week. If at any given time he has not plenty of food, this happens only because he has allowed his species to multiply too fast. He is able to cross the sea against adverse winds and place himself in a more fertile soil or under more genial skies than those of his former home. As respects all the primary needs of his life, he has so subjected Nature to himself, that he can make his life what he will. [Illustration: Neurdein