The World as Will
There can be no doubt that the second book of Schopenhauer’s main work contains the most important part, or at any rate the most crucial part, of the argument for his metaphysical position. It contains what he frequently refers to as the transition from phenomena to the thing-in-itself. It thus represents the other side of the coin to which I referred in chapter 4. While it does that it cannot be denied that the world as will is the more important side of the coin. If there were no phenomena, he sometimes says, there would still be will; but not vice versa. The thing-in-itself provides a kind of explanation of phenomena, but not one that involves the principle of sufficient reason. It does not explain each phenomenon taken separately; it explains them taken as a whole. That is, of course, something that Kant thought could not be the case in any positive sense. For him the concept of a thing-initself was a purely negative concept, required in order to provide a basis for phenomena but not in such a way that it can furnish any positive principles of explanation of them. Schopenhauer expresses the same urge for a basis for phenomena, saying, as I noted in chapter 4, that if we thought that the world was merely representation ‘it would inevitably pass us by like an insubstantial dream or a ghostly apparition not worth our consideration’ (WR I 17, p. 99; WI I, p. 128). He also admits that we cannot get at what he calls the ‘nature of things’ from without, from representation; for the principle that governs representations, the principle of sufficient reason, has no application outside them. He thinks nevertheless that there is available a clue to the nature of the thing-in-itself (and why we must speak in
Unfortunately, while Schopenhauer sets out clearly enough the order that the argument for the identification of the thing-in-itself must take, and follows that order in his presentation in the first volume of his main work, he is less clear about the details of the argument taken in that order. He does, however, provide us with all the materials for a reconstruction of that argument. On the whole, however, he is most anxious to give us the fundamentals of what he considered as his great discovery, which is in fact the conclusion of the argument. Thus in the first of the supplementary essays of the second volume which concern this part (WR II 18, p. 191; WI II, p. 399) he says that he has really published the essential supplementary essay in the work On the Will in Nature (published in 1836 in between the first and second editions of the main work), and in the chapter entitled ‘Physical Astronomy’ in particular. When one looks at that chapter, however, it does not seem to provide anything in the way of an argument, but rather a fairly systematic exposition of the conclusions of such an argument. It deals in particular with the ways in which different kinds of natural phenomenon can be viewed as subject to the same principles, mutatis mutandis, as those which apply to the manifestations of our own will. It is therefore concerned in effect with the claim that an insight into our own nature is really an insight into the nature of reality in general.