Identity and indiscernibility

Journal article

The notion of strict identity is sometimes given an explicit second-order definition: objects with all the same properties are identical. Here, a somewhat different problem is raised: Under what conditions is the identity relation on the domain of a structure first-order definable? A structure may have objects that are distinct, but indiscernible by the strongest means of discerning them given the language (the indiscernibility formula). Here a number of results concerning the indiscernibility formula, and the definability of identity, are collected and a number of applications discussed. © Copyright Association for Symbolic Logic 2011.

Authors: Ketland, J

• Journal: Review of Symbolic Logic
• Volume: 4
• Issue: 2
• Pages: 171-185
• Publication date: 2011-06-01
• DOI: 10.1017/S1755020310000328
• EISSN: 1755-0211
• ISSN: 1755-0203
• Language: English