Why Identity is Fundamental
Abstract
Identity is arguably one of the most fundamental concepts in metaphysics. There are several reasons why this is the case: Identity is presupposed in every conceptual system: without identity, it is unclear that any conceptual system can be formulated. Identity is required to characterize an individual: nothing can be an individual unless it has well-specified identity conditions. Identity cannot be defined: even in systems that allegedly have the resources to define identity. Identity is required for quantification: the intelligibility of quantification presupposes the identity of the objects that are quantified over. These are only four considerations in support of identity's fundamental role. In this paper, I examine and defend them. I then examine a challenge that has been raised against identity's fundamentality: one from the metaphysics of physics—based on a significant interpretation of non-relativist quantum mechanics—according to which certain quantum particles lack identity conditions. After responding to this challenge, I consider the nature of the commitment to identity, and argue that it turns out to be very minimal. In fact, a very deflationary form of metaphysics can accommodate it. In arguing that identity is fundamental, one need not overstep the boundaries of even a very minimal empiricist metaphysics. Or so I argue.