Quantity of Matter or Intrinsic Property: Why Mass Cannot Be Both

TL;DR

This paper critically examines the concept of mass in Newtonian mechanics, arguing that the traditional interpretation as quantity of matter is ill-defined and that as a property is metaphysically contingent on laws of nature.

Contribution

It offers a philosophical analysis of mass, clarifying its interpretative issues and exploring the metaphysical implications of different law theories.

Findings

Mass as a measure of matter is ill-defined

Mass as a property depends on metaphysical interpretation of laws

Different law theories influence the understanding of mass

Abstract

I analyze the meaning of mass in Newtonian mechanics. First, I explain the notion of primitive ontology, which was originally introduced in the philosophy of quantum mechanics. Then I examine the two common interpretations of mass: mass as a measure of the quantity of matter and mass as a dynamical property. I claim that the former is ill-defined, and the latter is only plausible with respect to a metaphysical interpretation of laws of nature. I explore the following options for the status of laws: Humeanism, primitivism about laws, dispositionalism, and ontic structural realism.