In the 'Introduction to Objectivist Epistemology' Ayn Rand contends that the famous 'problem of universals' is the great question that has lead to today's corrupt anti-reason philosophies, and that unless it is solved civilisation is toast.
But does she know what she's talking about?
Here's 3 issues that immediately stand out:
1) Is this such a potentially apocalyptic problem as she makes out? Nyquist argues persuasively that the claim that civilisation hangs in the balance is absurdly exaggerated.
2) It is not clear that Rand solved, or even really understood the problem of universals - which can be put simply as "how can different things still be similar?" For while admittedly the ITOE is anything but a coherent or systematic presentation, from what can be made out her ideas like "Conceptual Common Denominator" simply beg the question.
3) If universals are the problem, what has this got to do with Rand's obsession with Kant? Kant was replying to a very different problem: Hume's "problem of induction", which is a far more likely candidate for influencing the state of modern philosophy. Of course, Rand admits that she has not solved the problem of induction (on page 304 or 5 of the ITOE, from memory), and unintentionally also reveals she doesn't get this one either, as she says that one day some 'scientist' will solve it. But the problem of induction is not scientific; it is a logical problem.