Identity

Do Sentences Have Identity? - Article by Jean-Yves Béziau presented at the 20th World Congress of Philosophy.

The Identity of Indiscernibles - Entry by Peter Forrest in the Stanford Encyclopaedia of Philosophy. The principle is due to Leibniz, and states two entities are identical if they share the same properties.

The Paradox of Identity - Report by William Greenberg. Argues for a Hegelian account of identity.

Quantum Mechanics and the Identity of Indiscernibles - Essay by Allan Randall, relating Leibinz's criterion to Everett's possible worlds semantics of quantum mechanics.

Relative Identity - The view that there are objects which are the same F yet not the same G; from the Stanford Encyclopedia by Harry Deutsch.