law of identity

Definition of law of identity

  1. :  one of three principles in logic:

  2. 1 :  a statement (as “a house is a house”) in which the subject and predicate are the same is true

  3. 2 :  the copula in an identity affirms an existent of which the identity is true

  4. 3 :  a statement of an identity is the expression of an abstract relation of identity symbolized by a term (as A in “A is A”) that apparently refers in its separate instances to the subject and predicate respectively

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