Ipso Facto

Ipso Facto, ^* By the fact itself.

2. This phrase is frequently employed to convey the idea that something which has been done contrary to law is void. For example, if a married man, during the life of his wife, of which he had knowledge, should marry another woman, the latter marriage would be void ipsofacto; that is, on that fact being proved, the second marriage would be declared void ab initio.

^* From Bouvier's Law Dictionary, 1856 Edition. Please see Bouvier's Legal Abbreviations & Abbreviated References for help with obscure nomenclature & references.