 Although he defended moderate realism at the beginning of his career, Burley turned to an original form of radical, somehow Platonic, realism after 1324. This can be found in the prologue to his final commentary on the Physics, in his final commentary on the Ars Vetus, and in TdU, where he fully develops and explains his new semantic and ontological view. As noted above, the change was brought about by Ockham’s critique of the traditional realist view. In his Summa Logicae (pars I, chs. 14–15, and 40–41) and Commentary on the Categories (prologue, and chs. 7, §1 and 8, §1), the Venerabilis Inceptor had shown that many unacceptable consequences follow from the idea that universals are something existing in re, really identical with their particulars considered as instances of a type (e.g., the universal man qua man is identical with Socrates), but different considered as properly universal (e.g., man qua universal is different from Socrates). That is because whatever is predicated of the particulars must be predicated of their universals too, and so a unique common nature would possess contrary attributes simultaneously via the attributes of different particulars. Also, God could not annihilate Socrates or any other singular substance without at the same time destroying the whole category of substance and therefore every created being, since every accident depends on substance for its existence. For these and other similar reasons, Ockham concluded that the thesis that universals exist in re must be rejected.