 One of the novel claims in Geach’s Reference and Generality was that identity is relative in the strong sense that for two sortal expressions F and G, b and c might be the same F, but not the same G. Geach used the expression “substantival” to characterize the kinds of term F and G are. His “substantival” coincides in many cases with sortals as understood by others, but cannot be entirely the same since he cites “gold” as an example of a substantival, in fact: