They would have thought that Christianity is undeniably true, whereas Aristotelianism appears to be true. I doubt many of them would have put them at equal tiers of certainty, but otherwise, I agree.
It was controversial, of course; some would have taken the line you mention, others would have been harsher to Aristotle, and others apparently regarded them more equally. The doctrine of "double truth" which was attributed to the Averroists suggested that even where Aristotle disagreed with the church, he was still right philosophically while the church was right theologically. Whether any of the Averroists actually believed such an incoherent doctrine isn't clear, of course.
Yes, but I also point out that while the debate was about whether or not Aristotle was correct on this particular point, the main point of contention was that his position allegedly contradicted Catholic dogma.
I don't think it was. I think the main issue was what position was true, not which one was most consonant with Catholic teaching. It also wasn't really about Aristotle himself; that particular debate was conducted in its own terms, with everyone appealing to Aristotle where he supported them, Augustine where he supported them, and anyone else where appropriate - as was usually the case. Remember that
everyone, even supposed anti-Aristotelians such as Henry of Ghent, regarded Aristotle as an authority and appealed to him constantly. In such a context it was virtually impossible for Christian doctrine not to be interpreted in the light of Aristotle - the only question was how much. In the epistemological debate, it is true that one side was closer to Aristotle's own theory, but it wasn't cast in terms of "Aristotle or not", although later historians of ideas may have seen it like that. It was cast in terms of "Does it work like this, or like that?" and the real issue at hand was which theory best explained human cognition, not which one was most consistent with church doctrine. At least, that is how it appears to me.
The topic at hand is how much Greek philosophy influenced Christianity, and I would argue that it changed Christian thinking little per se. What was far more important was how it was adopted into Christianity via St. Thomas Aquinas and the like. If Aristotelianism was true, it was only true insofar that it was not contradictory of Catholic theology.
Right, but Christian theology isn't a set body of thought that people just inherit and can take or leave as they like. It develops and is re-interpreted, and one person may understand it differently from another. One may say that a medieval theologian interpreted Aristotle (or whoever) in the light of Christian teaching, but one might equally say that a medieval philosopher interpreted Christian teaching in the light of Aristotle. In practice it was surely a bit of both.
An example: consider the debate over the unicity of form. Aquinas thought that every substance has only a single substantial form, and if the form changes, you get a different substance. A living body has one form and a dead one has a different form. This yields the odd conclusion that when somebody dies, they are transformed into a new substance. In fact Aristotle thought this too, and held that a dead cat (say) is called a "cat" only homonymously - it is not really a
cat in the way that a live one is. Some people, most notably Robert Kilwardby and John Pecham, thought that this was absurd, and also heretical as it entailed that the dead Christ was a different substance from the live Christ. Defenders of the doctrine (not including Aquinas, who was dead when the dispute occurred) argued that this was not a heretical conclusion. So here we see a dispute of the kind you mention, where the issue is whether a certain claim is consistent with Christian teaching - but the reason there
was a dispute is precisely because people disagreed over what Christian teaching was. Some thought that it was a Christian teaching that the dead Christ be identical in substance to the live Christ, and others didn't. And their view on this matter was influenced, to some extent, by their philosophical commitments.
I'm likely wrong here, as I'm only a bit acquainted with Cartesianism, but wasn't this dispute based on a misunderstanding of Descartes' philosophy? He brings up an example of wax in the Meditation on First Philosophy, whereby the same object can take different shapes and forms depending on its circumstances, even though fundamentally it's the same substance, and uses this as evidence that our senses cannot be taken as inherently reliable before reason.
Yes, the wax example is supposed to show that we understand the world through reason rather than sense, because the wax can change properties and yet we recognise it to be the same thing - but Descartes would not have accepted that it could change
all its properties and yet remain the same thing. It was a fundamental tenet of Cartesianism - in fact arguably one of the most fundamental - that the essence of physical substance is extension (and the essence of mental substance is thought). Change the extension and you change the substance. If the wax were to change its extension, it would not remain the same thing. Conversely, if its extension does not change, its substance does not change, because the substance and the extension are exactly the same thing. This is why Descartes regarded the vacuum as conceptually impossible, because a vacuum is an area of extension that doesn't contain any substance (i.e. an empty space). In the case of the Mass, the bread's extension does not change, and neither do any of its other properties, yet it does become a different thing. That is also absurd on Cartesian principles. So this criticism wasn't based on a misunderstanding of Descartes at all - in fact many Cartesians recognised its force and wrapped themselves in circles trying to get around it. (Descartes himself didn't particularly care: his attitude to this sort of thing was "I've proved it, so if the theologians don't like it, that's their problem.")
I remain unconvinced that Catholicism is contingent upon Aristotelianism in order to be true. As highly revered as St. Thomas Aquinas is in the Catholic Church, his positions have not been declared infallible, so theoretically the Church could roll back to non-Thomistic theological outlooks.
Aristotelianism isn't the same thing as Thomism. To the extent that Catholicism requires you to distinguish between substance and properties, and to the extent that you call such a distinction Aristotelianism, Catholicism requires Aristotelianism. That's got nothing to do with Aquinas (who was around after the doctrine of transubstantiation was formulated - remember, as I said, that medieval metaphysics was deeply Aristotelian in many ways even before the rediscovery of Aristotle, thanks to the influence of the Categories and Porphyry). Of course you don't need the more specific arcana of Aristotelianism for that, only that basic principle, and I'd say it's a pretty reasonable principle, but it does still rule out some metaphysical systems, such as Cartesianism.
The example of medieval Aristotelianism isn't a very good one though, really, because the broad body of Christian doctrine was quite well established before these Aristotelian-specific points arose. I think a better example would be the blending of Christianity and Platonism in late antiquity, especially the third and fourth centuries - since Christianity was not so clearly defined then, and the philosophical influence was far greater. Classically educated theologians interpreted Christianity in ways drawn from their classical heritage. For example, figures such as the Cappadocians and Augustine re-invented Christian asceticism, of the kind that had been pioneered by Antony of Egypt and others, as a Christian version of the "philosophical life" championed by Cicero and other classical writers. In fact, Gregory of Nazianzus frequently uses the word "philosophy" as a technical term to refer to the life of Christian ascetic withdrawal and focus upon God. For these people, the practice of Christian religion and philosophy were exactly the same thing. Jaroslav Pelikan has written about this at some length in
Christianity and classical culture.
My point is not that Christianity in general depends on any given philosophical system or set of ideas, because it clearly doesn't. But I do think that the various particular forms that Christianity has historically taken tend, as a rule, to depend upon at least elements of, and sometimes most of, the prevalent philosophical systems of the time.