And further, in order to be felt, this action does not require that we should have a more or less clear knowledge of it. Even at the time when man knew almost nothing of the laws of nature, his activity was more or less controlled by them. The ends sought after by man have always depended upon his moral and physical nature: the reason of the failure or the success of his efforts have always been found in the natural laws. Gradually positive knowledge was developed. Man became conscious of the order by which he is himself surrounded, of which he feels himself to be a portion, and in which his intellect collaborates in a measure difficult to determine but yet certain. The external regulator which, whatever our will may be, imposes itself upon our activity is thus revealed to our mind. The last degree to be reached is that it should finally be accepted by our feeling. This is precisely the result obtained by positive philosophy. For it makes us know our individual and social nature. It has shown us that humanity must not be explained by man, but man by humanity. It has explained the growing development of social life and that of altruism, which is at once its condition and its consequence. We now understand that our benevolent affections find themselves “spontaneously in conformity with the natural laws which govern the development of society.”[331] Thus it is the continual pressure of external order which makes our egotistic instincts capable of being trained. They would undoubtedly get the mastery, if our sympathetic inclinations did not find without, in the laws of nature, a constant support which reason ends by understanding. Moral perfection would be harmony realised among all men, by their mutual goodwill, according to the principle: _Live for others_, and, at the same time, harmony realised in each individual soul, by the subjection of egoism to the altruistic sentiments. But this harmony is not what is produced in the first place. On the contrary, war rages between the social groups, discord between the members of the same groups, the passions in each individual soul. Sometimes one, sometimes another of our tendencies influences us, according to circumstances whose details vary to infinity. No stable order of subordination is established among our tendencies: human nature, considered by itself, does not contain any principle which could maintain such an order. Left to itself, the human soul would remain in the state called by Spinoza “fluctuation.” The moral problem would have no durable solution. Hence the necessity of a “universal brake,” to make sure of the development of the altruistic tendencies. This brake is no other than the inevitable and continual pressure of the order of the world upon our conduct, and in the long run, _upon our motives_.