The article discusses the importance of understanding the institutional structure of criminal law in determining what conduct is justified or excused. It argues that trial courts do not decide what is justified after the fact, but rather this decision is made beforehand by other institutional actors. The study emphasizes the need to consider the division of labor within the legal system before addressing specific moral or legal questions. By looking at areas like private law and public administrative law, we can better understand justification defenses and the overall structure of criminal law.