For my PhD, I intend to work on building a suitable reconstruction of Rudolf Carnap’s famous internal/external distinction (ESO 1950) as extended to the realism/anti-realism controversy by William Demopoulos (Extending ESO 2011). In what follows, I will clarify my research goals and their philosophical motivations.
With regard my research on Carnap, I am one of those people who think that, in addition to its historical significance, his internal/external distinction has philosophical merit in the contemporary realism/anti-realism literature. Carnap’s distinction in its original form may appear to oversimplify the realism controversy and to introduce an artificial demarcation of formal language forms. The former problem is especially apparent in Carnap’s caricature of metaphysical debates (Elimination (1932), Problems (1934), Testability (1936), ESO (1950), and recurrent in Schlipp Volume (1963)). The latter objection is a main part of Quine’s criticisms of Carnap’s distinction (Ontology 1951). Nevertheless, I believe a suitable reconceptualization of Carnap’s distinction is warranted. As for the tenability of such a reconstruction, Demopoulos’s Extending ESO (2011) is a useful example of how feasible it is to articulate a defence of the distinction (against, for example, Penelope Maddy’s Second Philosophy 2007).
I intend to advance Carnapian literature by first articulating a reconstruction of Carnap’s distinction. I will then explore the ramifications of this reconstruction. In particular, I want to rethink Carnap’s structuralism in virtue of the reconstructed distinction, especially against the notorious Newman objection. The philosophical incentive for such a conceptual exploration is well-motivated because Carnap’s Ramsey-sentence approach to scientific theories appears to allow him to both sidestep the problem of “surplus meaning” (or excess content)—which arises from the liberalization of the verification principle (Testability 1936)—and to provide a better explication of ‘analyticity’ for the theoretical language form of science (Theoretical Concepts 1959) and overcome Quine’s criticisms (Two Dogmas 1951).