Heidegger's 1936 F. W. J. Schelling lectures begin by accepting the mutability of Schelling's thought that Hegel notes, but dispute that these diverse expressions express correspondingly different philosophical positions. Schelling's so-called Fichtean period is Fichtean to the extent that the latter's philosophical innovations form the linchpin for Schelling's critical analyses of the form and possibility of a true philosophical idealism. Schelling's philosophy of nature comprises three major books and the essays published in the Journal of Speculative Physics and New Journal of Speculative Physics and the Annals of Scientific Medicine. The philosophy of nature, Schelling writes, is the 'physical explanation of idealism'. Schelling casts the problem of creation in terms of the emergence of order from disorder. Order and form are not original; rather, 'the unruly was brought to order' echoing the Platonic cosmology from which his studies began. Hegel's objection to Schelling that he never had a single system turns out to a necessary consequence of that 'unique standpoint'.