Armstrong, David Malet - Universals: An Opinionated Introduction

The topic of universals is a very old one. It goes back to Plato at least, perhaps to Socrates, perhaps to even earlier times. Those contemporary philosophers who pay the matter attention often speak of the Problem of Universals. So let me begin by saying what the problem is. It may turn out that it is really a pseudo-problem. That was the opinion of Wittgenstein and his followers, for instance. Quine is not far from thinking the same. But whether it is a real problem or not should not be decided in advance.