James Ladyman

James Ladyman: "Identity, Individuality and Discernibility"

James Ladyman (University of Bristol) "Identity, Individuality and Discernibility". Listen to the talk here.


Structuralism is often construed as a claim about individuation to the effect that it is somehow dependent on relations. The notion of ontological dependence may be modelled by derivability in a formal language. Such languages may have different resources, for example, they may or may not include names. The formal correlate of the metaphysical content of the identity of indiscernibles can be construed as the reduction of identity to predication involving qualitative properties and relations. It has been argued that so-called 'weak discernibility' is sufficient for such a reduction. Furthermore, weak discernibility turns out to be the weakest non-trivial form of discernibility. In this talk I explain the recent debates about the Principle of the Identity of Indiscernibles and recent results about weak discernibility, and consider their implications for structuralism and what light they shed on the notion of ontological dependence.