Back مبدأ الهوية Arabic Principi d'identitat Catalan یاسای ھەرھەمانی CKB Identitetsloven Danish Ταυτότητα (μαθηματικά) Greek Principio de identidad Spanish قانون هویت Persian Principe d'identité French חוק הזהות HE Principio d'identità Italian
In logic, the law of identity states that each thing is identical with itself. It is the first of the historical three laws of thought, along with the law of noncontradiction, and the law of excluded middle. However, few systems of logic are built on just these laws.