The author develops the foundations for the retrospective assessment of the severity of a crime, allowing for a rational and consistent determination of penalties. The starting point is the critique of the so-called margin theory and a guilt understanding that is heavily oriented towards the personality of the offender. As an alternative, the theory of crime-proportional sentencing is proposed, which determines the degree of punishment and thus the level of social-ethical reproach solely based on the severity of the act. The author advocates for the use of categories from criminal law for a structured sentencing process. The penalty, therefore, corresponds in most cases to the harm caused and the wrongful action, while the category of guilt can only be relevant to sentencing in the form of mitigating factors. After a detailed discussion of the factors for assessing harm and wrongful action.