Abstract for Tübingen Summer School 2014 – Comparativism about mass in Newtonian Gravity

The property of having mass is a determinable with two types of determinates: we think of an object with mass as having a determinate intrinsic property, but we also think it stands in determinate mass relationships with other massive objects. Absolutism is the metaphysical position that the intrinsic properties are fundamental; the mass relationships are then grounded in those intrinsic masses. Comparativism is the position that the mass relationships are fundamental; they are all there is to the property of having mass (Dasgupta, 2013). In line with the topic of this summer school, the comparativist about mass views the intrinsic masses merely as the conventional ‘scaffolding’ on top of which the `arches’ (i.e. the mass relations) are built – it is high time to remove this redundant scaffolding.

The absolutism-comparativism debate is a debate about the correct counting of possibilities/possible worlds. Dasgupta’s version of the main (only?) argument in favour of comparativism claims that 1) intrinsic masses are, in principle, undetectable (i.e. they generate metaphysically distinct possibilities that are, in some sense, not physically distinguishable), and on top of that 2) comparativism is ontologically more parsimonious. Hence, we should choose comparativism over absolutism.

I will suggest that the argument in its current form is not valid, but even after modification it remains unsound, since both premises are false, or so I argue.

I first argue against claim 1, by discussing several modal arguments against comparativism, where I focus on developing Baker’s ‘Earth/Pandora argument’ (forthcoming). I argue that Baker’s own analysis of the argument is mistaken. Comparativism recognizes less possible worlds than our (deterministic) physics requires (i.e. a specification of comparativist initial conditions results in an indeterministic evolution of the system), rendering intrinsic masses detectable after all. The argument – pace Baker – does refute comparativism, at least in its standard (non-mixed) form. I furthermore show (if time allows) that even Dasgupta’s adaptation of Lewisian counterpart theory using mass-counterparts will not save the comparativist.

Even if claim 1 would hold, this would be insufficient, since comparativism – despite first appearances – is ontologically less parsimonious than absolutism. Although the non-locality, in the sense of non-seperability, of comparativism is an issue, what is fatal is that comparativism presupposes a miraculous conspiracy between all the mass relations of all the objects in the universe.