How to ground (higher-order) identities

Abstract The purity principle requires that identity truths such as “Hesperus is identical to Phosphorus” are grounded. This argument from purity for the groundedness of identity truths for first-order entities can be naturally generalized to higher-order identities like “to be a vixen is to be a female fox.” In this paper, I will examine various accounts of the grounds of identity truths by taking the cases of higher-order identities into consideration. Drawing on some essentialist insights, I will propose a novel account and argue that it offers an attractive explanation of how identities, including both first-order and higher-order cases, are grounded.