use, for censure's sake, has been made, against this system, of the seeming ease with which its professors have convinced themselves that they cut up by the roots the very principles of morality and duty. History proves, by examples too infamous, that barbarism and license are the privilege of no philosophic sect. The real enemies of society always have been, and always will be, the ignorant and the fanatical, and it must be frankly owned that, if these exist within the pale of materialism, there are quite enough of them outside. The danger in the doctrine which reverses the natural relation of things, and asserts that spirit is a product of matter, when in truth matter is a product of spirit, this danger is of another kind; materialism is fatal to the development of the experimental sciences themselves. If, in such a case, the example of men of genius might be appealed to, how eloquent would be the testimony of the two greatest physicists of this age, Ampère and Faraday, both so earnestly convinced, so religiously possessed by the reality of the unseen world! But there are other arguments. "All that we see of the world," says Pascal, "is but an imperceptible scratch in the vast range of Nature." The claim of mere experimentalism is that it may sentence men to the fixed and stubborn contemplation of this scratch. What folly! All the history of the development of the sciences proves that important discoveries all proceed from a different feeling, which is that of a continuation of forces beyond the limits of observation, and of a harmony in relations, overruling the singularities and deformities of detached experiences. To hedge one's self within what can be computed, weighed, and demonstrated, to trust such evidence only, and bar one's self inside the prison of the senses, to hush or scorn the suggestions of the spirit, our only true light, because it is a spark of the flame that vivifies all—this is, deny it or not, the condition and the subject state of materialism. Only reason can conceive the fixity, the generality, and the universality of relations, and all savants admit that the destiny of science is to establish laws possessing these three characteristics; but to admit that is to confess by implication that partial, incoherent, imperfect, relative details must undergo a refining, a thorough conversion, in the alembic of the mind, whence they issue, with so new an aspect and meaning, that what before seemed most important becomes as mere an accessory as it is possible to be, and that which looked most ephemeral takes its place among eternal things.
The conception of atoms dates from the highest antiquity. Leucippus and Democritus, the masters of Epicurus, several centuries before the Christian era, taught that matter is composed of invisible but indestructible corpuscles, the number of which is as boundless as the vastness of the space in which they are diffused. These corpuscles are solid, endowed with shape and motion. The difference of their forms regulates the difference of their movements, and consequently of their characteristics. The conception of a principle guiding these diversi-
