intellectual evolution,—"this most remarkable of all natural formations." He did not become acquainted with the French-English positivism until later. He calls himself a positivist, but at the same time emphasizes that the essential element of positivism consists in its empirical starting-point, rather than its systematic conclusion. He says: the positivist proceeds step by step, with a constantly widening horizon.
He elaborated his theory of evolution in connection with an analysis of the Kant-Laplace theory which he regarded a typical example of the scientific method of explanation (La formazione naturale nel fatto del sistema solare, 1877). The present state of the solar system came into being by a process of separation (distinzione), in which smaller bodies (distinti) were formed within larger undifferentiated bodies (indistinto). The larger body is not destroyed by this process. It persists and forms the basis of the interaction of the smaller body. There exists therefore an inherent continuity between the larger body and the smaller bodies which constitute its parts. The possibilities potentially contained within each of these indistinto (as "forze latente or virtuale") can only be developed by interaction with other objects! Each indistinto is therefore in turn a part of a more comprehensive whole, so that the distinction between indistino and distinti is merely relative. Science is here confronted by an infinite series of processes; but its only task consists in explaining the fundamental relation of indistinto and distinti in each particular case, because it assumes that all differences, no matter where they occur, proceed from one whole and are forever comprehended within it.
The theory of knowledge is but a special case of the general theory of evolution. Every explanation consists
