It may be remarked that this doctrine is not confined to any particular school or sect. Leibniz was by no means a materialist, and he endowed his mundane elements, his _monads_, not only with a sort of life, but even with a sort of soul. Father Boscovitch, Jesuit as he was, and professor in the college of Rome, did not deny to his _indivisible points_ a kind of inferior vitality. St. Thomas, too, the angelical doctor, attributed, according to M. Gardair, to inanimate substances a certain kind of activity, inborn inclinations, and a real appetition towards certain acts. CHAPTER II. ORIGIN OF BRUTE MATTER IN LIVING MATTER. Spontaneous generation: an episode in the history of the globe—Verification of the identity between brute and living matter—Slow identification—Rapid identification—Contrary opinion—Hypothesis of cosmozoa; cosmic panspermia—Hypothesis of pyrozoa. There should be two ways of testing the doctrine of the essential identity of brute and living matter—one slow and more laborious, the other more rapid and decisive. _Identification of the Two Matters, Brute and Living._—The laborious method, which we will be obliged to follow, consists in the attentive examination of the various activities by which life is manifested, and in finding more or less crude equivalents for them in all brute beings, or in certain of them. _Rapid Verification. Spontaneous Generation._—The rapid and decisive method, which, unhappily, is beyond our resources, would consist in showing unquestionable, clearly marked life, the superior life, arising from the kind of inferior life that is attributed to matter in general. It would be necessary completely to construct in all its parts, by a suitable combination of inorganic materials, a single living being, even the humblest plant or the most rudimentary animal. This would indeed be an irrefutable proof that the germs of all vital activity are contained in the molecular activity of brute bodies, and that there is nothing essential to the latter that is not found in the former. Unhappily this demonstration cannot be given. Science furnishes no example of it, and we are forced to have recourse to the slow method.