This legal maxim means “ignorance of law is no excuse”.
The legal Maxim Ignorantia Legis semi nem excusat imposes that ignorance of the law is no excuse. When a person commits a mistake, he can take the mistake of fact as a defense but he cannot take an excuse of the mistake of law as a defense. Blackstone states: “Every man must be taken to be cognizant of the law, otherwise there is no knowing of the extent to which the excuse of ignorance might be carried. It would in almost every case”
In a leading case of Ram Rawaloo Gawade v. Satya Gawadoo (1990 (1) SCC 261), the court laid the exception of this maxim. The Appellant, in this case, was an illiterate farmer and he wanted to become a necessary party after the demise of his uncle. As the appellant was illiterate and needed legal counseling by a legal expert, the matter was delayed. The Appellant did not have proper counseling on time. Thus, the court held that the principle laid down in this maxim will be exempted in this case