The authenticity of "Epinomis" has also been questioned on the grounds of its philosophical content. Leonardo Tarán, while finding parallels for many of the allegedly un-Platonic elements of the dialogue's style, declared it spurious based on (in the words of a sympathetic reviewer) "the much firmer ground of the misunderstanding or contradiction of Platonic doctrines, such as the placing of astronomy above dialectic as the supreme object of study, the rejection of the Ideas, the introduction of a fifth element, aether, between fire and air, and the elaborate theory of daemons inhabiting the three middle elements." Werner Jaeger detected the influence of Aristotle's "On Philosophy" (a lost work Jaeger believed to have been published shortly before "Epinomis" in 348/347 BC) on much of the "Epinomis", including the idea of the "fifth body."