 In quantum theory there are even fewer candidates for intrinsic properties. Even in elementary quantum mechanics, the closest analogue of a point particle as classically understood (“a quantum particle”) is an all-pervading field, viz. an assignment, for each instant of time, of a (complex) number to every point of space. Here, the mass of the quantum particle cannot be attributed to any single point of space, but must be associated with the whole field, although not in the simple manner of “spreading the mass out” as a classical mass density distribution. (The same remark applies to the quantum particle’s charge.) Turning to quantum field theory: here again, the notion of particle is radically changed from the idea of a classical point particle and from the idea of a quantum particle. There are not various quantum particles, each of them represented by a complex-valued field as above, and each of them, say, electrons. Rather there is a single all-pervading electron field and each electron, as treated in elementary quantum mechanics, is replaced by a unit of energetic excitation of the electron field. The same goes for other types of matter, such as quarks. According to quantum field theory, quarks are really excitations of an all-pervading quark field. Besides, quantum field theory exhibits a second, and fundamentally different, way in which mass and charge fail to be intrinsic properties. This goes under the label of “renormalization”. In short, the mass and charge of a particle à la quantum field theory, i.e., a unit of excitation of an all-pervading field, depends upon the length-scale at which you choose to describe, or to experimentally probe, the field (Butterfield 2014, 2015).