Observational discrepancies in galactic rotation curves and cluster dispersion data have been interpreted to imply the existence of dark matter. Numerous efforts at its detection, however, have failed to turn up any positive result. As a dynamical theory is always operative on the assumed mass distribution to predict kinematic observations, some scientists see the discrepancy as telling against General Relativity. Among the many theories that seek to modify gravity, those that are built on Modified Newtonian Dynamics (MOND), or yield MOND (...) behaviour at appropriate scales, achieve remarkable empirical success without assuming dark matter. The continued non-detection of dark matter and the empirical success of MOND supports the claim that the current evidential and theoretical context underdetermines General Relativity. In this article, I clarify the kind of underdetermination that can be said to threaten General Relativity. Specifically, I argue that the present evidential and theoretical context increase the possibility of an unconceived alternative to GR which would be just as well supported by the available evidence. (shrink)

Underdetermination of theory choice claims that empirical evidence fails to provide sufficient grounds for choosing a theory over its rivals. We explore the epistemological and methodological significance of this thesis by utilising a classificatory scheme to situate three arguments that purport to establish its plausibility. Proponents of these three arguments, W.V.O Quine, John Earman, and Kyle Stanford, use different premises to arrive at the conclusion that theory choice is empirically underdetermined and their classification along the proposed schema brings out the (...) variety in underdetermination arguments and the historical trajectory of the thesis. Although the epistemological significance of underdetermination—it is seen as undermining the doctrine of scientific realism—is widely discussed in the literature, Quine understood the acceptance of the thesis as interrogating the attitude one is justified in adopting towards rival theories. We argue that sticking with one’s own theory in the face of underdetermination leads to a distinct type of disagreement, which we present as the methodological significance of underdetermination. The examination of the methodological significance of underdetermination allows us to propose weak underdetermination as a philosophically interesting variant of underdetermination. (shrink)