  Among conceptions of propositions as structured entities one can distinguish, roughly, between Russellian and Fregean versions. Both the Russellian and the Fregean conceptions of propositions are families of theories. In general Fregean theories will take a proposition to be a complex entity with a particular structure whose constituents are senses. But senses are abstract objects. And if, as seems plausible, a complex entity whose constituents are abstract objects must be an abstract object itself (how could an object be in space or time when its constituents exist neither in space nor time?), then, on this account, propositions are abstract objects.