  From his earliest days at Princeton, Sylvan had argued that an adequate philosophy of science required quantification over non-existent objects (numbers, frictionless planes, etc.), and an adequate semantics for fictional discourse was also best pursued along these lines. (Cf. Routley 1965, 1966a, 1979a; Routley and Routley 1973b, 1979a.) For reasons discussed in Section 3 below, he followed Meinong in seeking a theory that includes non-existent objects, and a logic that can handle such objects.