In a bold series of pronouncements, Arthur Schopenhauer maintains that the Kantian thing-in-itself is Will. The division between the world as Will and representation, with its impressive array of implications, is Schopenhauer's most important and distinctive contribution to metaphysics. To understand what Schopenhauer means by ‘Will’ as opposed to the empirical ‘will’, and his reasons for identifying thing-in-itself with Will, we must look in detail at two related arguments by which Schopenhauer proposes to link these concepts. The arguments appear in (...) the first and second editions of Schopenhauer's masterwork, The World as Will and Representation. The differences between the two versions appear to represent a change in his thinking about the most persuasive way to demonstrate the nature of thing-in-itself. The arguments are reconstructed for the sake of comparison, and critically evaluated in light of a variety of objections. While Schopenhauer's first, analogical, argument is inconclusive, his second argument offers a highly defensible inference identifying thing-in-itself as Will. (shrink)