  This general problem of semantic variation remains in the background, since many features other than simple supposition were attributed to terms, but the nature of the debate about concepts and things was to change completely in the fourteenth century, first with the insistence of John Duns Scotus, like others before him, that individuals can be grasped by the intellect, but more especially with the rise of nominalism, according to which all that exists are individual things, and that only concepts can be common or universal. The question whether words primarily signify concepts or things was now construed as the question: does a word signify an individual thing in the world directly, or does it signify first the concept which is a necessary condition for signification? John Buridan and his near contemporary William Ockham differed on this issue. Buridan held that words first signify concepts, because only then can we explain why terms such as ‘being’ and ‘one’ which have the same extension nonetheless differ in signification. Ockham preferred to say that words signify only individual things and are subordinated to concepts without signifying them. Both thinkers are noteworthy for their insistence that the concept itself was a sign which plays a crucial intermediary role in language production and understanding and that concepts are the terms of a fully-fledged mental language. Moreover, the concept as sign was defined as a formal representation of its object. However one construes the notion of representation here (and any crude pictorial theory can be ruled out), it is clear that conceptual representation was taken to involve some level of generality, and so there is an obvious problem where singular concepts are concerned. Yet, given John Buridan’s claim that a spoken term cannot be called universal or singular unless it corresponds to a universal or singular concept, we must have singular concepts if we have any genuine singular terms. As we shall see in §9, Buridan introduces an extra condition for the singular concept, while allowing it to have a certain kind of generality.