Ich rate mal, hab das Wort noch nie gehört oder verwendet, ist vermutlich Wirtschaftssprache: wertrationalität, wertrational

This relates to your question is there the word "Wertvernunft" in German. But, domasla is right: there is no such word. Your context is philosophy, and sometimes I think that maybe "Vernunft der Werte" or "Vernunft von Werten", meaning that there is always a reason, a sense, a point, in values may mean this. Does this come closer to your concept?

Since I know already, that you're dealing with modern western philosophy, I think you're are referring to Max Weber or Jürgen Habermas. Both researched the orientation for communicative actions. So if you're talking about taking the decision on base of general rules and norms, then the word you look for is: "Wertrationalität" (dingdingding, kraut9 is the winner! ;)) The philosophic opposite (and true source of Wertrationalität? heheh :P) is btw. "Zweckrationalität" or "intention rationaliy" Daniel