18.] As the whole science, and only the whole, can exhibit what the Idea or system of reason is, it is impossible to give in a preliminary way a general impression of a philosophy. Nor can a division of philosophy into its parts be intelligible, except in connexion with the system. A preliminary division, like the limited conception from which it comes, can only be an anticipation. Here however it is premised that the Idea turns out to be the thought which is completely identical with itself, and not identical simply in the abstract, but also in its action of setting itself over against itself, so as to gain a being of its own, and yet of being in full possession of itself while it is in this other. Thus philosophy is subdivided into three parts: I. Logic, the science of the Idea in and for itself. II. The Philosophy of Nature: the science of the Idea in its otherness. III. The Philosophy of Mind: the science of the Idea come back to itself out of that otherness. As observed in § 15, the differences between the several philosophical sciences are only aspects or specialisations of the one Idea or system of reason, which and which alone is alike exhibited in these different media. In Nature nothing else would have to be discerned, except the Idea: but the Idea has here divested itself of its proper being. In Mind, again, the Idea has asserted a being of its own, and is on the way to become absolute. Every such form in which the Idea is expressed, is at the same time a passing or fleeting stage: and hence each of these subdivisions has not only to know its contents as an object which has being for the time, but also in the same act to expound how these contents pass into their higher circle. To represent the relation between them as a division, therefore, leads to misconception; for it co-ordinates the several parts or sciences one beside another, as if they had no innate development, but were, like so many species, really and radically distinct. [1] The journal, too, edited by Thomson is called 'Annals of Philosophy; or, Magazine of Chemistry, Mineralogy, Mechanics, Natural History, Agriculture, and Arts.' We can easily guess from the title what sort of subjects are here to be understood under the term 'philosophy.' Among the advertisements of books just published, I lately found the following notice in an English newspaper: 'The Art of Preserving the Hair, on Philosophical Principles, neatly printed in post 8vo, price seven shillings.' By philosophical principles for the preservation of the hair are probably meant chemical or physiological principles.