Such was the condition of infant man; the life of an animal limited at first to mere sensations, and hardly profiting by the gifts nature bestowed on him, much less capable of entertaining a thought of forcing anything from her. But difficulties soon presented themselves, and it became necessary to learn how to surmount them: the height of the trees, which prevented him from gathering their fruits, the competition of other animals desirous of the same fruits, and the ferocity of those who needed them for their own preservation, all obliged him to apply himself to bodily exercises. He had to be active, swift of foot, and vigorous in fight. Natural weapons, stones and sticks, were easily found: he learnt to surmount the obstacles of nature, to contend in case of necessity with other animals, and to dispute for the means of subsistence even with other men, or to indemnify himself for what he was forced to give up to a stronger.