 Insofar as ideas are modes, they occupy the lowest rung on Descartes’ ontological ladder. This can be contrasted to Plato’s theory, for example, which casts ideas as substances, occupying the upper-most rung of the ontological ladder. So, whereas for Plato ideas are the most real things in the cosmos, for Descartes ideas are among the least real. Another departure from Plato’s view was Descartes’ taking ideas as the vehicles of representation, as the items doing the representing. By contrast, Plato took ideas to be the things represented. Socrates, for instance, was taken by Plato to be a representation of the form or idea of man. These differences are certainly enough to suggest that ideas are playing significantly different roles in their respective systems. So, it would not be reasonable to think that Descartes’ view was simply an extension of Plato’s, despite the fact that Descartes had adopted some of Plato’s terminology.