Identity, Ontology, and Frege's Problem

It is argued that the semantic difference between sentences of the form ”a = a” and ”a = b” reflects a difference in their truthmakers. My account of these truth-makers combines a referential semantics – singular terms are deemed to contribute nothing but their reference to the meaning of sentences in which these occur – with an ontology of logically complex individuals. Against analyses in which Fregean senses are invoked to account for the difference in meaning between (sentences of the form) “a = a” and “a = b”, this ontology invokes an Aristotelian notion of identity as oneness in substance as the source of this difference, rendering Fregean senses otiose.