 Given this definition, is Vasubandhu, the author of the Twenty Verses and the Thirty Verses and probably the Three Natures Exposition, a metaphysical idealist? At first blush, it seems quite sensible to say that he is. The evident purpose of the Twenty Verses is to argue that the core background assumptions of Mahāyāna Buddhism (especially its views on karma) suggest the idealistic thesis that is asserted in the text’s opening: “In the Great Vehicle, the threefold world is only  appearance.”[44]  Vasubandhu argues throughout the Twenty Verses that whatever aspects of the world appear to be independent of mind, they are better explained as mental constructions. What that means is, apparently, that not only is Vasubandhu an idealist in the sense that he believes that everything in experience is dependent upon mind, but he also believes that everything simply is mind. This is the radical “mind only” (cittamātra) position that he believes is necessitated by adherence to a Mahāyāna worldview.