PL
In this paper author presents the achievemenets of Leon Petrażycki and his novelty in various areas of humanities. Petrażycki is recognised as forerunner of deontic logic, and also as creator of the principle of adeqacy, ennoblement of law, pluralistic vision of law. He exhibits primacy of legal norms over moral norm, and he establish scientific legal policy. Additionaly Petrażycki is treated as classic of the sociology of law and also as the artificer of emotions.