Abstract

The following statement (A) is usually abbreviated with symbols: (A) There are items X and Y, each is F, X is not identical to Y, and everything F is identical to X or is identical to Y. (A) is neither necessary nor sufficient for the existence of exactly two distinct things that are F. Some things are neither identical nor distinct. The difference between distinctness and nonidentity makes a difference in asking questions about counting, constitution, and persistence.