Objects and Structures: Some (Further) Remarks Concerning the Motivation for Ontic Structuralism and its Metaphysical Characterisation

Elaborating on existing work, this paper discusses so-called ontic structural realism – the view according to which a) we can, and did in the past, gain knowledge of the structure of reality through our best science, and b) structure is all there is (or, at least, structure is metaphysically fundamental and prior to objects). In line with earlier criticisms of the view, the strength of ontic structural realism is questioned on several grounds. In the first part, it is contended that the two arguments normally put forward in favour of ontic structural realism – one from metaphysical underdetermination, the other based on the alleged priority of relations over objects – are not persuasive. In particular, the role played by the Principle of the Identity of the Indiscernibles in the argument from underdetermination is discussed in some detail, with a view to dissolving some misunderstandings of previous critiques. In the second part, it is argued that the prospects for defining a complete metaphysics for ontic structural realism are dim. In particular, either no convincing account of the ontological priority of relations over objects is available; or, if it can be provided, the resulting view of things suffers from the above mentioned lack of motivation.