Normative morals invariably, though perhaps not quite necessarily, come with normative epistemological accompaniments. I say not quite necessarily, since it is perhaps possible to imagine a morally normative yet epistemologically sceptical system. Such a system would make explicit the temporary, pragmatic aspect of the moral rules that it proposed. Whether it would truly be a normative system of morals rather than an objective description of the operation of other systems of morals is open to question. The fact that such a sceptical system has never appeared or at least survived long enough to form a societally universal and distinctly visible system gives one reason for thinking that something in this tentative normativity does not function in accordance with human requirements and that the system is therefore fragile.
For all practical, historical purposes, then, we observe that normative morals and epistemological freedom are incompatible, and that all moral systems insist on a normative epistemology to reinforce the integrity of their foundations and their protective shell (shields are as important as logical roots). In essence a set of instructions is placed in and around the moral framework forbidding observation or the interpretation of observations in specified areas of experience. This is part of the reason that status-shifted societies, which rely heavily on normative moral systems, are so hostile to science, as compared to contract-shifted societies.
Thus, there is an inevitable conflict between Morals and Science. Free observation undermines the normative epistemological foundations and punctures the defensive shell, and this conflict will continue as long as observation fails to detect any transcendent aspect to the universe that is supportive of the existing normative moral system or is capable of supporting a new moral system.