The distinction between the force/mode of speech acts and intentional states and their propositional content has been a central feature of analytic philosophy since Gottlob Frege and Bertrand Russell. Proponents of the force-content distinction (FCD) therefore hold that all logical operations operate on forceless propositions and that all propositions, whether atomic or molecular, negated, disjunctive, conditional or conjunctive, require a separate, additional act in order to be judged or asserted to be true. Though naturalistically inclined philosophers were of course never sympathetic to Frege's Platonism about propositions, this typically only led to attempts to replace propositions with declarative sentences or classes of such sentences. The traditional unity problem is the problem of how the constituents of a proposition can be so related that they constitute a representation of states of affairs rather than a mere list. Mark Textor gives an account of attitude reports as part of his project of a defense of a restricted version of the FCD.