But we know that the study of embryonic origins does not suffice to make us understand animal life, which is not a scheme, but is composed of living beings which struggle, and in their struggle employ forces, instincts and passions. And it is the same, _mutatis mutandis_, with men also, in so far as they live historically. These particular men, moved by certain passions, urged by certain circumstances, with such and such designs, such intentions, acting in such an attempt with such an illusion of their own, or with such a deception, of another, who, martyrs of themselves or of others, enter on harsh contests and reciprocal suppressions of each other--there is the real history of the French Revolution. If, however, it is true that all history is but the unfolding of definite economic conditions, it is equally true that it develops only in definite forms of human activity,--whether the latter be passionate or reflective, fortunate or unsuccessful, blindly instinctive or deliberately heroic. To understand the interlacings and the _complexus_ in its inner connection and its outer manifestations; to descend from the surface to the foundation, and then to return from the foundation to the surface; to analyze the passions and the intentions, in their motives, from the closest to the most remote, and then to bring back the data of the passions and of the intentions and of their causes to the most remote elements of a definite economic situation; there is the difficult art which the materialistic conception must realize. And as we must not imitate that teacher who on the bank taught his pupils to swim by the definition of swimming, I beg the reader to await the examples which I shall give in other essays in a real historical narration, working over into a book which for some time I have already been doing in my teaching. In this way certain secondary and derivative questions are once for all cleared up. What, for example, is the meaning of the lives of the great men? In these later times, answers have been given, which, in one sense or another, have an extreme character. On the one side, there are the extreme sociologists, on the other side the individualists who, after the fashion of Carlyle, put the heroes into the first rank of their history. According to some it is sufficient to show what were the reasons, for example, of Caesarism, and Caesar matters little. According to others, there are no objective reasons of classes and social interests which suffice to explain anything; it is the great minds which give the impulse to the whole historic movement; and history has, so to speak, its lords and its monarchs. The empiricists of narration extract themselves from embarrassment in a very simple fashion, putting together at hazard men and things, objective necessities of fact and subjective influences.