Akademik

identity
All of us agree with Joseph Butler that everything is what it is and not another thing. The difficulty is to know when we have one thing and not two. A rule for telling this is a principle of individuation, or a criterion of identity for things of the kind in question. In logic, identity may be introduced as a primitive relational expression, or defined via the identity of indiscernibles . See also personal identity.

Philosophy dictionary. . 2011.