The Ultimate Justification of Moral and Legal Reasoning

As stated before, legal reasoning is supported by reasonable premises. A reasonable premise is not falsified and not arbitrary. A premise is thus reasonable if, and only if, the following conditions are fulfilled:

• 1. The premise is not falsified.

• 2. The hypothesis is not to a sufficiently high degree corroborated that this premise does not logically follow from a highly coherent set of premises.

In consequence of this definition of reasonableness, the theory of rationality, presented above, is logically dependent upon a theory of coherence. One must thus make the justification even deeper and discuss the concept of coherence. The discussion of this concept, presented in this section (4.1), follows closely a paper on the subject, jointly prepared by Robert Alexy and myself (Alexy and Peczenik 1989).

Since a long time, the idea of coherence has been regarded as an attractive tool for solving epistemological problems (cf., e.g., Hegel 1970, 24). The idea is applicable in many different contexts. A theory can thus be coherent with data. One theory can be coherent with another. Legal rules can be coherent with moral principles. Interpretation of a statute can be coherent with moral principles and such sources of the law as precedents; and so on.