following observation will, I conceive, be admitted without much dispute. So long as inquirers are apt to step un- wittingly across the boundaries that separate one province of knowledge from another, so long, and in the same degree, does the whole course of their intellectual operations depend on outward circumstances : for it is only a systematic dis- tribution of the whole field that can lead to a regular and connected cultivation of it. In the same way, so long as the several sciences are pursued singly, and their respective vo- taries contentedly acquiesce in this insulation, so long, and in the came degree, is the specific instinct for the object of each science predominant in the whole sphere of intellectual exertion. But as soon as the need of the connexion and co- ordinate growth of all the branches of knowledge has become so distinctly felt, as to express itself by the form in which they are treated and described, in a manner which can never again be lost; so far as this is the case, it is no longer par- ticular talents and instincts, but the general scientific talent of speculation, that has the ascendant. In the former of these cases it must be confessed, that the idea of science as such is not yet matured, perhaps has not even become the subject of consciousness, for science as such can only be con- ceived as a whole, in which every division is merely subordi- nate, just as the real world to which it ought to correspond. In the latter case, on the contrary, this idea has become a subject of consciousness ; for it can have been only by its force that the particular inclinations which confine each thinker to a certain object, and split science into insulated parts, have been mastered. And this is unquestionably a simpler criterion to distinguish the two periods of Greek philosophy. In the earlier period, the idea of science as such was not the go- verning idea, and had not even become a distinct subject of consciousness : and this it is that gives rise to the obscurity which we perceive in all the philosophical productions of that period, through the appearance of caprice which results from the want of consciousness, and through the imperfec- tion of the scientific language, which is gradually forming itself out of the poetical and historical vocabulary. In the second period, on the other hand, the idea of science has become a subject of consciousness. Hence the main business
