 Complex propositions are subject to a generalized version of what is now called the Frege-Geach problem. In a conditional proposition, for example, it might seem that one could affirm the conditional without separately affirming its components. But in the Logic, the propositions constituting the antecedent and consequent are formed by an act of affirmation (or denial). The proposition, “If the Earth is flat, then astronomy needs revision” should be affirmable without one’s accepting the antecedent as true, i.e., without affirming it.