A moral principle which also acknowledges its opposite must be reliant on practical situations that can be unanimously and unequivocally interpreted, and where it can be firmly settled whether the principle or its opposite is to be applied. In so far as situations for such interpretation are lacking, the principle loses both its value as a means of orientation and its normative function. For it could provide justification for each and every decision.

QUESTION: If a principle can justify every decision, does it truly bind conduct at all, or only in idealized cases?

Niklas Luhmann, Trust and Power, loc. 304