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

Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Join MWU now and get access to America’s largest dictionary, with:

  • 300,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Seen and Heard

What made you want to look up law of identity? Please tell us where you read or heard it (including the quote, if possible).


to criticize severely

Get Word of the Day daily email!