The concept of human dignity often encounters criticism, either as too thick or too thin. However, firstly, if one takes the non-positivistic standpoint, then it is to be admitted that the legal normativity of human dignity can be justified and therefore strengthened by its moral correctness. Secondly, it would be better observed that the image of man has dual dimensions, that is, both the individual and the social dimension. From the individual perspective, in order to understand adequately the formula of ‘man as an end in itself’ and hence the human dignity as an intrinsic value, the key lies in the differentiation as well as connection between principium diiudicationis and principium executions, between will and choice (Willkür), and those between homo phaenomenon and homo noumenon (that is, humanity in the personality). Based on this understanding of human dignity, the rights of man, the free association of citizens as well as the criminal justice can be rationally justified.