Reference was made in the last chapter to the fact that one of the difficulties in determining whether a thinker such as Husserl is a realist or idealist is the multitude of senses with which those terms are used. It is, for example, no small irony that in the Middle Ages those who most vigorously defended a realist position were the inheritors of a position sometimes called idealistic. These medieval realists, of course, defended the Platonic or strong position that universals had an ideal existence separate from individuals, and they were opposed by the nominalists who claimed that only individuals, including general terms, exist. Intermediate positions were certainly available. We must, for example, consider Aristotle a realist, although his realism regarding universals is a moderate form asserting that universals have a real existence only as principles or abstract moments of individuals. Similarly, we must consider Abelard's conceptualism a nominalism, although general terms refer not directly to collections of individuals but to an individual idea, whose extension ranges over similar individuals.