"In short, for everyone engaged in scientific discourse, statements must be subject to validation by methods and criteria which are, in principle, not subject to partisanship, whatever their ideological consequences, and however motivated. Statements not subject to such validation may nevertheless be important and valuable, but belong to a different order of discourse. They pose extremely interesting and difficult philosophical problems, especially when they are clearly in some sense descriptive (for example, in representative art or criticism 'about' some specific creative work or artist), but cannot be considered here. Nor can we here consider statements of the logico-mathematical type, insofar as they are not (as in theoretical physics) linked to validation by evidence."