Theorists of criminal law almost unanimously argue that criminal law is a science, that statement is critical to the terms on which construction takes place, since the scientific allows this knowledge systematization which constitutes the cornerstone of all legal concepts. Is the system real? Within this article it questions the existence of such a system, that as a result of judicial discretion, which is presented in the ongoing activity in the general law and criminal law. Judicial discretion therefore makes it look fuzzy dear regulations in punitive system, which generates a bead-scientific the concept and which in turn represents a real calamity for the law: his illegitimacy.