 The inertial mass in Newtonian physics (and even the gravitational mass) is routinely interpreted as an intrinsic property of an object. The inertial mass of an object is a measure of the body’s inertia, i.e., its tendency to resist changes to its state of motion in response to the action of any kind of force. Since at least the late nineteenth century and Mach’s criticisms of Newton’s physics, physicists have deprecated thinking of mass as the “quantity of matter.” 