Alexander Broadie, The Shadow of Scotus: Philosophy and Faith in Pre-Reformation Scotland, 22-23:
I should say, as an aside and perhaps tendentiously, that the fact that voluntarism is a progenitor of ethical relativism might well, all by itself, make us hesitate to ascribe at any rate an unqualified voluntarism to Duns Scotus. Had the relevant Vatican authorities sensed the slightest whiff of relativisim in Scotus' writings, he would assuredly not have been accorded the title beatus. The recent encyclical letter Veritatis Splendor by John Paul II contains a strongly worded denunciation of moral relativism in all its forms. For example, in its opening paragraph the encyclical describes the results of original sin in these terms: 'Giving himself over to relativism and scepticism man goes off in search of an illusory freedom apart from truth itself.' And later the encyclical declares: 'The primordial moral requirement of loving and respecting the person as an end and never as a mere means also implies, by its nature, respect for certain fundamental goods, without without which one would fall into relativism and arbitrariness' (para. 48).
The presence of these and similar assertions in the encyclical is not however one of my reasons for thinking that Scotus was not in any full-blooded sense a relativist in his teaching on the existence of values. Their presence is merely a reason for holding that others who would speak with authority on the question of whether Scotus was a relativist or not must have thought that he was not one. My own reasons for holding that Scotus was no relativist are not grounded in the authority of others. Instead they are all firmly grounded in Scotus's own clear statements of his position -- I am speaking about statements in which he attaches morality very firmly indeed to right reason, and makes clear his belief that we can by the exercise of reason learn how we ought to behave. Consulting the Bible is therefore not the only route to the truth about moral matters. We can of course consult the Bible, and will find the truth if we do. The point is that we can also find the truth by cvonsulting our reason. In Lecture Three I shall cite some of the relevant passages in Scotus's Ordinatio.
Just by way of contrast with MacIntyre, let's look at Broadie's authorities for this particular chapter.
John L. Mackie, Ethics: Inventing Right and Wrong
John Paul II, Veritatis Splendor
That's it for the in text citations. The chapter is on intellectualism vs. voluntarism, realism vs. nominalism. There is talk of Henry's position on the will, and Scotus' formal distinction. There is a page plus some change of notes at the end of the chapter, in which Broadie cites the following:
Wolter, Duns Scotus on the Will and Morality
B. Bonansea, On Duns Scotus' Voluntarism
Kant, Critique of Practical Reason
Beck, A commentary on Kant's critique of Practical Reason
Duns Scotus, Opus Oxoniense, II d. 16 q. un. (latin quotation)
Aquinas, Summa theologiae, pt. 1 q. 77 (latin quotation)
Mark Henninger, Relations: Medieval Theories, 1250-1325
More latin quotes from Scotus same place as above
Aristotle, Metaphysics (English quotation).
So Broadie cites real scholars on Scotus as well as famous figures from the tradition. He also quotes the texts of Scotus to support his interpretions. The only thing one can fault him with is his use of this particular passage of the Ordinatio, since in fact it is not part of the original draft of the Ordinatio.Instead, it is from Alnwick's additions to Book II. But this isn't Broadies fault, since the critical edition had not come out when he wrote his lectures. And even now, it's not at all clear that the Roman Commission's method of handling this was correct; they decided the text was inauthentic because of its association with Alnwick. But Alnwick was Scotus' secretary, and Scotus might very well directed the material from the Reportatio be inserted into the Ordinatio. The jury is still out on this question.
This may well seem circular to outsiders: only Scotus experts can be cited on Scotus and Scotus experts don't agree with the Thomist interpretation. My answer to this is that Scotus is the victim of centuries of propaganda, from Protestants as well as Thomists, so, yes, only Scotus scholars are competent to discuss Scotus in broad strokes or to discuss his "worldview". When it comes to the level of arguments, I can only encourage postmodernists, protestants and Thomists to quote Scotus or at least justify their interpretations from people who know what they are talking about, and then show where individual arguments go astray. Example: Scotus' theory of univocity is either true or false. If you, as a Thomist, know a priori that it is false, then you owe us poor benighted Scotists an explanation of what fallacy Scotus committes or which premise in his argument is false.
Bottom line: Michael Sullivan is an expert since he has a Ph.D. and did his dissertation on Scotus and 13th century philosophy under the head of the new Scotistic Commission of America (which is currently editing the Parisian works of Duns Scotus). I am an expert since I am finishing up my dissertation on Duns Scotus and 13th century philosophy, have studied under two other members of the Scotist Commission, and am currently a member of said commission (though as the most junior member I make the coffee runs). This doesn't mean we are right about everything, but it does mean we know what we are talking about when it comes to medieval philosophy, and that certain historians do not.