“[T]he Platonist ideology (at least in the Straussian view) is that its zetetic character is meant as an antidote to ideology—the Socratic exaggeration that the only knowledge is knowledge of ignorance.” (The third comment here)
Suddenly, a couple of things are making sense, or at least they are becoming more relevant.
The Socratic method of enquiry may not carry the full weight of Cartesian doubt, but its dialogical path might have foretold the uncertain Frenchman. As opposed to Descartes, Plato’s vision of ideals was so heavenly that his material existence was made bearable and given meaning … though the search for those ideals basically constituted a life almost solely bent on transforming our ignorant state – not just into a knowing existence, but into the ideals themselves.
So Plato really has a vision for a better reality (that may or may not be concrete), but at least as far as he is received through his texts, and the “zetetic” method in them, we the readers are put on the train of seeking an ideal existence, whether or not we would be satisfied simply with knowing it. Descartes would be satisfied with knowing it, ultimately for the same reason Plato or Socrates might – that knowledge, in their terms, is defined by being untethered from the restraints put on us, end desirable for that reason.
Later on, some philosophers chafed at this kind of abstraction, and insisted on practical knowledge as something valuable, and done in a different way. St. Thomas did, and Kant, but the really important break came when Marx claimed to collapse all of philosophy into a study of praxis: “The philosophers have only interpreted the world, in various ways: the point is to change it.” Thus the study of social reality totally eclipsed the study of essences, which all previous philosophy had been concerned with.
Leo Strauss was among those in the 20th Century intent on reversing that monstrosity. All good and well regarding political science, rightly understood. But Socratic enquiry does not necessarily point to an end, unless we just take the end to be knowledge itself. But the Christian vision is not just beholding the truth of God, but experiencing His goodness – even in Thomas’s beatific vision, these are essentially converging. Plato has no such end, because experiencing is particular, and therefore tied down.
In philosophical terms, it is profound to say that “the only knowledge is the knowledge of ignorance” – but it is only profound if that ironic humility gives us intimations of God. This mental quest is an interesting path, but the strictly duty-bound “good life” therefore envisioned by Aristotle, or Kant, is wide open to assault from Rousseauean pity.
When existentialism meets virtue ethics, the result cannot be foreseen by either, because neither Plato nor ourselves can envision transcendence merging with immanence … which is why the Incarnation of Christ completely changes the terms of debate. By demonstrating the shortfalls of Plato’s ideal Knowledge, the vision itself changes; rather than providing a new solution to an old problem, the philosophical venture itself (again, as defined by Plato) is depressed to a lower level, and not just because we “know in part,” but because the predicatory life itself is defined in new terms.