France the population increases more slowly than in other European nations, the average duration of life is greater. The higher the average duration of life, the greater the accumulation of productive forces. The reason why war is so fatal to civilization, even among the conquerors, is that it destroys those who are at the age most favorable for production.
We have now to consider the third element of civilization, as found in man himself, and this is the most important of all, namely, the intensity of force. Two equal quantities of individuals will not in the same space of time produce equally, for each may not possess the same energy, the same intensity of life or force. Individual values are determined by the development of organs, functions, and faculties, which come in part from exercise and culture, and in part from inheritance. On the one hand, we have the habits acquired by the individual, which are modified by his surroundings; and, on the other hand, we have habits rooted in the family, nation, or race, and which become hereditary. The latter is called an instinct, and embraces all those sentiments which men have in common, their intensity being in proportion with the social progress which produced them. The influence of these inherited sentiments is very great, though it is frequently overlooked. If a man is what he is as distinct from all others in virtue of individual development and personal character, we are men having our specific and race character from inheritance. We are possessed of the apparatus of vision, hearing, language, circulation, digestion, because these functions are so many habits that have become essential to the human race.
These habits and instincts are not all good, for vices too are habits. This means only that the action of our organs and faculties sometimes takes a direction unfavorable to society or humanity. The body has its diseases, the understanding its errors, and the will its vices. Entire races have sometimes depraved instincts, which forbid their advancing beyond a certain degree of civilization, while others fail to attain that intellectual development which is the condition of all ulterior progress. Now, what is the criterion for determining what habits are good and favorable for civilization? We need only apply our general formula, and then we shall see that those habits have a civilizing influence which tends to increase man's forces, the power of his faculties, his value as an intellectual or material producer. On the contrary, those habits which have a tendency to deprave the individual, weaken his faculties, or efface his moral instincts, are vices which, when generalized and transmitted, whether by education or by inheritance, lead a people toward decay, decrepitude, and extinction. The ideas, instincts, and moral habits of the individual, are ever in competition, and, when this competition tends toward perfection, the element which wins in the struggle always gains power by selection.
It was the fashion during the eighteenth century to regard the
