Jacques Derrida has been accused of writing in a deliberately obtuse and obfuscated manner, so the relationship between his work and that of Plato's might not be immediately discernible. Perhaps the clearest connection between the two can be derived from Derrida's of Grammatology, especially as it compares to Plato's aesthetics and view of reality. In this rather dense treatise, Derrida first outlines the phenomenon of what he calls logocentrism -- the attitude that speech (logos in Greek) is the most basic and essential form of language, while writing is secondary in development and its ability to reflect meaning. Derrida claims that logocentrism has long been a silent and foundational part of Western thought, even from the time of Plato.

Plato believed that truth and meaning existed in a pure state somewhere, with the shadows of meanings existing in our own world. Derrida sees this as a flawed worldview, though not without potential. He uses some of Plato's thinking to deconstruct logocentrism. If speech is merely a representation of thought, and writing just a representation of speech, than writing is a representation of a representation -- the evil mimesis of Plato's aesthetics. Through his method of deconstructing such binary oppositions, Derrida makes it clear (or at least as clear as he ever makes anything) that both speech and writing our subservient to each other, and actually create meaning. This has to do with the deceptively simple concepts of presence and absence -- writing is present for the reader, whereas speech is always-already absent, having passed before the thoughts it contains can be processed. Derrida then claims not hat writing is more important than speech, but that both are equally adept at creating meaning and not merely represnting it; there is no...

Aristotle proposed another opposite to Plato's conception of mimesis. He agreed that all art was mimesis -- an imitation -- but noted that humans were naturally imitative creatures. But despite the fact that all humans had the capability of mimesis, it is also easily noted that some are better at it than others. That is, some imitations were better at achieving the emotional release or catharsis that Aristotle thought should be the aim of all art, especially drama (Poetics, 1449b). Therefore authorship was of immense importance to Aristotle. Each author was an individual conduit of imaginative imitation that could never again be produced, and meaning was created by individual interpretation.
Foucault's essay "What is an Author?" can be read as a direct extension of such Aristotelian beliefs. He comments on our tendency to imagine authors as isolated beings, not admitting that they are products of their times. He also nots that their words do not exist in a vacuum, and thoughthe words of a book would not change if it was discovered to have been written by a different author, our perception of those words and their meanings would. Meaning -- not just words themselves, the representations of meaning -- is subjective, according to Foucault. This makes the question of authorship of great importance in establishing truth.

It should be clear now why it is said that Plato is to Derrida as Aristotle is to Foucault. The concepts of aesthetics and truth follow a convoluted path over the millennia between the two sets of philosophers, and the issues are still unresolved.