Two characteristics distinguish quantities from non-quantitative properties and relations. First, every quantity is associated with a class of determinate “magnitudes” or “values” of that quantity, each member of which is a property or relation itself. So when a particle possesses mass or charge, it always instantiates one particular magnitude of mass or charge — like 2.5 kilograms or 7 Coulombs. Second, the magnitudes of a given quantity (alternatively, the particulars which instantiate those magnitudes) exhibit “quantitative structure”, which comprises things like: ordering structure, summation/concatenation structure, ratio structure, directional structure, etc. We often represent quantities using similarly-structured mathematical entities, like numbers, vectors, etc.
The metaphysics of quantity concerns the nature of these features. Questions in the metaphysics of quantity include: how are quantities related to numbers? Are some physical quantities intrinsic to objects? What role do quantitative features play in laws of nature? In virtue of what do a quantity’s determinates exhibit metric, or other quantitative structure?
Maya Eddon – University of Massachusetts, Amherst
David Baker – University of Michigan
Jessica Wilson – University of Toronto
Cian Dorr – New York University
Brent Mundy – Syracuse
Erica Shumener – New York University (Ph.D. Candidate)
Zee R Perry – New York University (Ph.D. Candidate)