My thoughts about ceratin linguistic conventions have a tendency to create breakdowns in communication, so it might behoove me to leave this note for anyone yet to scroll down the page:
'Orthodoxy' is not a normative term. It is a non-rigid designator for a particular kind of subgroup within a larger group that satisfies a certain cluster of definite descriptions. The paradigm instances of the larger groups are religions and political movements, though there are certainly other kinds. An orthodoxy in an ideology (or whatever else) is composed of a subset of adherents of the ideology in such a way that the subset has the following emergent feature: the various ideological beliefs of the subset's members come to define, in some broad and robust sense, the rational expectation of what the beliefs of any adherent of the ideology will be, so that it is a borderline analyticity that anyone who subscribes to the ideology assents to its orthodoxy, partially or categorically. What is phenomenologically interesting about orthodoxy is that there needn't be any alternative faction within the ideology for there to be an orthodoxy within it, merely the epistemic possibility of tension between the minimal definition of the ideology in general and the minimal definition of the orthodox interpretation of it --- and that's because borderline analyticities are also borderline syntheticities.
Everyone who has a passing familiarity with the practice of politics knows that orthodoxy is a real phenomenon. The unfortunate thing is that even intelligent people use 'orthodox' as a normative modifier (almost always pejoratively). The fact that a belief is orthodox has nothing to do with whether or not it is true or false. Nothing follows from the fact that a belief is orthodox, except that it is orthodox. The normative 'uses' of orthodox are genetic fallacy. All of us, but especially those of us who are optimists about the ability of the knowledge of the truths of logic to cure a substantial proportion of contemporary philosophical and ideological pathologies have a responsibility to prevent the adherents of bad logic from defining linguistic convention.