Language, Action and Thought

Essentialism, as defended for instance by (Ellis, 2001), (Bird, 2015) and (Lowe, 2004), is one of the main theories of natural kinds. In this talk I will introduce a new formal semantics for an essentialist theory of kinds formulated in classical (and non-modal) two-sorted monadic first-order logic. Instead of the standard semantics, I will make use of R. Wille’s algebraic Theory of Concept Lattices. Whereas the former represents kinds simply as sets of objects (and in the modal case, as functions from worlds to sets), the latter represents them as pairs of sets (A, B), where A contains the members of the kind and B contains the attributes that form the general essence of the kind. The semantics will be shown to be complete with respect to the theory and will be compared to other formal approaches, such as (Thomason, 1969), (Martin, 1997) and (Freund, 2019). In contrast to the first two, the current approach captures the essentialist membership conditions of kinds. In contrast to the third approach, it gives a more nuanced account of the hierarchical structure of the specificity relations between kinds. Based on these reasons, I argue that this approach is preferable as an explanation of natural kind essentialism.