If the confusion between Logic and the Doctrine of the Categories, or between the thinking of the logical category and the thinking of the other categories, had produced no other effect than that of introducing into books of Logic a method of treatment that exceeds their bounds, the evil would not be great. It would chiefly affect literary harmony and clarity of didactic exposition. But from that confusion there has sometimes as _rational Philosophy and real Philosophy,_ sometimes as _Gnoseology and Anthropology (or Cosmology,)_ sometimes as _Logic and System of Philosophy,_ and so on. The conception of Reality is thus twice described: once as part of Logic (the Doctrine of the Categories, Ontology, etc.); and again as effective or applied Philosophy. Philosophy is divided into a Prologue to Philosophy and Philosophy, or into Philosophy and a Conclusion to Philosophy. But Philosophy, although it is distinguishable into philosophies (for example, Æsthetic, Logic, Economic and Ethic), _is this distinction itself,_ or the unity immanent in it. It never gives rise to a duality of grades. It is never prologue, development and conclusion, being, at its every point, prologue, development and conclusion. As from empirical and formalist Logic arose the idea of a Logic which should not be philosophy, but an organ or instrument or rule or law for the rest of philosophy; so from the confusion of Logic with the Doctrine of the Categories has arisen the idea of a Logic, or Metaphysic, or general Philosophy, or whatever else it may be called, which should be _opposed to or above_ the rest of philosophy. But the Science of thought, Logic, is at once thought and effective philosophy; it is thought itself which in thinking the Real, thinks itself and places itself, as logical Science, in the place which belongs to it in the system of the Real. [Sidenote: _Philosophy and pure logic: overcoming of the duality._] It may seem that in this way thought and reality are again divided and a metaphysical dualism created. But the exact opposite is the truth. When Philosophy is distinguished into general and particular, into rational and real, into pure and applied, into Logic-metaphysic and into Philosophy of nature and of man, an irreparable breach is made, which can only be concealed or attenuated in a more or less ingenious manner. But when that doubleness of degree is destroyed (and thought thinking the real thereby thinks itself), and in the construction of Philosophy, the Philosophy of philosophy, namely Logic, is constructed, the dualism is for ever overcome. This thought is the thinking of the distinctions, which the real presents; but to think distinctions and to think unity is, as has been already demonstrated, the same thing. [Footnote 1: _Logik,_ pp. 532-3.] [Footnote 2: See above Sect. II. Chap. V.] SECOND PART PHILOSOPHY, HISTORY AND THE NATURAL AND MATHEMATICAL SCIENCES I THE FORMS OF KNOWLEDGE AND THE DIVISIONS OF KNOWLEDGE