development of the organs, not their exercise and the development of their functions. Hunger, regarded by him as the primary and universal feeling, has for its object the appropriation of matters coming from without. It is a force of concentration and absorption into itself. But, as we have seen, nutrition and the restoration of the organs, which simply store up the forces of tension by a kind of negative work, are not the real source of positive pleasures or of positive pains. It is in expending the energy of materials already appropriated that we feel pleasures and pains. In that way are brought about the development of the being and evolution toward new conditions of life: the living being acts upon the medium, and the medium is in turn modified by the increasing power of the being. There is, therefore, in animated nature a development from within to without, and not only a kind of envelopment and absorption from without by that which is within. The acquisition and restoration of the tissues suppose a certain activity already present, an anterior outbreak of life manifested by movement; and it is plausible to suppose beneath this vital movement, preceding the rudimentary pain caused by the exterior resistance, the rudiment of pleasure attached to the interior action.
The conclusions to which our study appears to have brought us are not less important for the theory of morals than for the theory of man and of the world. The first is, that natural selection, a wholly mechanical and exterior process, presupposes an internal principle of evolution, which principle is an activity capable of enjoying and suffering. A second conclusion is, that pleasure is immediately connected with action, and comfort with existence and the unfolding of life. Hence it follows that pain is not, as some of the pessimists believe, the principle of internal action and desire, but only that of the reaction on the external world.
Extending these results to the general theory of the world, we can infer from them that pain is not the sole motive of universal evolution. It is only at the origin of evolution that uneasiness, pain, or hunger, is the principal spur of which Nature avails herself. But in a higher degree in the scale of beings, pleasure, through the intervention of the thought that anticipates it, becomes the certain stimulus to activity. Hence, we have seen the higher senses effecting rapid condensations of an infinity of delicate and subtile pleasures, objects of luxury rather than of the necessities of material life; and evolution becoming a child of wealth, and not a child of poverty only. For this reason evolution does not seem to us to be solely "preservation of self," according to Darwin's term, or "maintenance of the normal equilibrium"; but it is, or may become, a progress. Pain, therefore, is not, as Schopenhauer and Yon Hartmann maintain, the eternal and irremediable condition of beings, a kind of damnation, or a hell from which the world can not escape except by annihilation of itself.
Still other moral consequences, no less important, are brought out.
