It follows from all that has been said that it is certainly an error on the part of natural science to seek to refer the higher grades of the objectification of will to the lower; for the failure to recognise, or the denial of, original and self-existing forces of nature is just as wrong as the groundless assumption of special forces when what occurs is merely a peculiar kind of manifestation of what is already known. Thus Kant rightly says that it would be absurd to hope for a blade of grass from a Newton, that is, from one who reduced the blade of grass to the manifestations of physical and chemical forces, of which it was the chance product, and therefore a mere freak of nature, in which no special Idea appeared, _i.e._, the will did not directly reveal itself in it in a higher and specific grade, but just as in the phenomena of unorganised nature and by chance in this form. The schoolmen, who certainly would not have allowed such a doctrine, would rightly have said that it was a complete denial of the _forma substantialis_, and a degradation of it to the _forma accidentalis_. For the _forma substantialis_ of Aristotle denotes exactly what I call the grade of the objectification of will in a thing. On the other hand, it is not to be overlooked that in all Ideas, that is, in all forces of unorganised, and all forms of organised nature, it is _one and the same_ will that reveals itself, that is to say, which enters the form of the idea and passes into _objectivity_. Its unity must therefore be also recognisable through an inner relationship between all its phenomena. Now this reveals itself in the higher grades of the objectification of will, where the whole phenomenon is more distinct, thus in the vegetable and animal kingdoms, through the universally prevailing analogy of all forms, the fundamental type which recurs in all phenomena. This has, therefore, become the guiding principle of the admirable zoological system which was originated by the French in this century, and it is most completely established in comparative anatomy as _l’unité de plan_, _l’uniformité de l’élément anatomique_. To discover this fundamental type has been the chief concern, or at any rate the praiseworthy endeavour, of the natural philosophers of the school of Schelling, who have in this respect considerable merit, although in many cases their hunt after analogies in nature degenerated into mere conceits. They have, however, rightly shown that that general relationship and family likeness exists also in the Ideas of unorganised nature; for example, between electricity and magnetism, the identity of which was afterwards established; between chemical attraction and gravitation, and so forth. They specially called attention to the fact that _polarity_, that is, the sundering of a force into two qualitatively different and opposed activities striving after reunion, which also shows itself for the most part in space as a