The explanation lies in the simple fact that progress is not a phenomenon of individual life at all. It is a phenomenon of social existence. If each generation had to commence at the exact point at which its predecessors started it would get no farther than they got. It would be an eternal round, with each generation starting from and reaching the same point, and progress would be an inconceivable thing. But that we know is not the case. Instead of each generation starting from precisely the same point, one inherits at least something of the labours and discoveries of its predecessors. A thing discovered by the individual is discovered for the race. A thought struck out by the individual is a thought for the race. By language, by tradition, and by institutions the advances of each generation are conserved, handed on, and made part of our racial possessions. The strength, the knowledge, of the modern is thus due not to any innate superiority over the ancient, but because one is modern and the other ancient. If we could have surrounded the ancient Assyrians with all the inventions, and given them all the knowledge that we possess, they would have used that knowledge and those inventions as wisely, or as unwisely as we use them. Progress is thus not a fact of individual but of racial life. The individual inherits more than he creates, and it is in virtue of this racial inheritance that he is what he is. It is a mere trick of the imagination that converts this fact of social growth into an essential characteristic of individual life. We speak of "man" without clearly distinguishing between man as a biological unit and man as a member of a social group developing in correspondence with a true social medium. But if that is so, it follows that this capacity for growth is, so to speak, a function of the social medium. It is conditioned by it, it has relevance only in relation to it. Our feelings, our sentiments, even our desires, have reference to this life, and in a far deeper sense than is usually imagined. And removed from its relation to this life human nature would be without meaning or value.