The Logic and Metaphysics Workshop will meet on December 5th from 4:15-6:15 (NY time) via Zoom for a talk by Martin Pleitz (Muenster).

**Title**: Reification as identity?

**Abstract**: Abstract objects like properties and propositions, I believe, are the result of reification, which can intuitively be characterized as the metaphysical counterpart of nominalization (as in the shift, e.g., from ‘is a horse’ to ‘the property of being a horse’; cf. Schiffer, Moltmann), and occurs paradigmatically in the well-known bridge laws for instantiation, truth, etc. (e.g., something instantiates the property of being a horse iff it is a horse). So far, I have been working on an account of reification in terms of the technical notions of encoding & decoding, as some regulars at the L+M workshop may recall. In my upcoming talk, I wish to embed reification more clearly in higher-order metaphphysics and explore an alternative idea: Can reification be construed as *identification across metaphysical categories*? E.g., can the *object* that is the property of being a horse be *identified*, in some sense, with Frege’s *concept horse*, which is a non-objectual item because ‘is a horse’ is not a singular term? In my presentation I will argue for an affirmative answer. For this, I will sketch an ultra-generalized logic of equivalence, which has as its special cases (i) the well-known logics of first-order identity and equivalence, (ii) recent logics of generalized identities (à la Rayo, Linnebo, Dorr, Fine, Correia, Skiles, …) which connect higher-order items of the same type, and (iii) the logic of my proposed cross-level equivalences which connect items of different types. In a second step, I will re-construe reification as the cross-level equivalence that holds between higher-order items and abstract objects of the appropriate sort and argue that this account of reification as identity has certain advantages.