ABSTRACT
Over the past sixty years or more—ever since Quine was seen as reviving metaphysics in the wake of the positivist attacks—metaphysics has been dominated by neo-Quinean methodology, so much so that some simply refer to neo-Quinean metaphysics as “mainstream metaphysics” (Manley 2009, 4). On the neo-Quinean conception, metaphysics is “of a piece with” scientific inquiries, and they are jointly devoted to finding the best “total theory.” Yet the neo-Quinean approach is also thought to give metaphysicians serious and difficult work to do in determining what really exists.1 The metaphysician has work to do, first, in helping determine what our best theories are (weighing up the theoretic virtues of competing theories), and second, in determining what (when best expressed in canonical first-order logic) those theories commit us to. We are then to believe the ontology required by our best theories.2 The work is neither empirical nor conceptual (indeed those two cannot be separated, according to the neo-Quinean view); instead, it involves a kind of weighing up of theories on grounds of criteria such as simplicity, explanatory power, unity with other theories, etc. As Sider writes: “Admittedly, those criteria give less clear guidance in metaphysics than elsewhere; but there's no harm in following this argument where it leads: metaphysical inquiry is by its nature comparatively speculative and uncertain” (2011, 12). The work indeed has proven so difficult and uncertain that during the reign of neo-Quinean metaphysics we have seen a great proliferation of metaphysical views rather than anything like convergence.
