ABSTRACT
I present in this chapter two different challenges to dispositional essentialism, the view that at least some fundamental properties possess dispositional characters essentially. The challenge from categoricalism, which denies that fundamental properties possess any dispositional essence, motivates dispositional essentialists to adopt a hybrid view, according to which the essence of a fundamental property does not only consist of dispositional characters, but also categorical characters. However, as I demonstrate, this hybrid position is inconsistent with the common assumption that the categorical, unlike the dispositional, is non-modal. Likewise, the challenge from modern physics requires dispositional essentialists to revise their conception of the dispositional in order to accommodate new findings in quantum mechanics, such as invariance quantities and symmetry principles.
