In my last post, I explained why I find the evidence in favor of substance dualism convincing over hylomorphic dualism. Since what I'm about to say is somewhat disconnected from the last post, I felt I should save it for later. Nevertheless, I thought I should say something about the historical narrative often painted around substance dualism when brought up in connection with hylomorphic dualism. Before beginning though, I want to say that I consider hylomorphic dualists more of an ally against materialism than enemies; that I truly sincerely seek the truth here and also seek to be faithful to my Catholic Christian beliefs; and finally that I do not intend for any of my comments to be rude or disrespectful to the people I am disagreeing with, as I take their position seriously and try my best to understand it on its own terms.
Now, basically, you sometimes hear it claimed that substance dualism led to materialism, that substance dualism brought about a metaphysical revolution at the expense of scholasticism, that substance dualism leaves behind the consensus of the greatest philosophers, that substance dualism helped bring about the downfall of western civilization, etc. Usually the trouble is supposed to have started with Descartes' formulation of substance dualism. Now, many philosophers would probably just dismiss these questions as irrelevant, but I honestly take these points a bit more seriously than most, at least to the extent that I take quite seriously the arguments and thoughts of many of the people who were not substance dualists--like Aristotle and Aquinas.
First, how I think we should handle these sorts of claims in general:
-While I'll say some things in defense of Descartes, note that I defined substance dualism quite minimally earlier, as the theory that the soul is an immaterial substance distinct from the body and we are identical to the soul. Hence, it is extremely important to note that not everything which can be ascribed to Cartesian metaphysics can thereby be ascribed to substance dualism.
-We have to be careful to avoid slippery slope fallacies, of the form "This belief had or has such and such undesirable effects, therefore it's false."
-When writing our narratives, we should be careful about painting too broad a picture or making very tenuous connections between ideas or figures and historical facts.
-The best narrative will be good history, and when it comes to the history of philosophy that is best accomplished by looking at the ideas the philosophers actually held.
-When seeking the truth we should focus primarily on arguments, not persons or narratives.
Second, what I think is correct in these sorts of claims:
-Many people who were greatly influenced by Descartes abandoned scholastic metaphysics for no good reason whatsoever.
-After Descartes scholastic philosophy did not have a very large role in early modern philosophy.
-Cartesian metaphysics is different in important ways from many of the preceding metaphysical systems.
-Belief in substance dualism does in fact have certain ethical implications, though I don't think they are as radical as some people make them out to be.
Third, where I think these sorts of claims are wrong:
-Substance dualism in no way entails materialism. It is a theory of how the mind is not material. Now if you say that the idea of materialism could not have developed were it not for substance dualism, I reply that first, Leucippus and Democritus existed before Descartes, and second, materialism could not have developed were it not for many things, including the belief in matter, yet this does not impugn in any way our belief in matter.
-Substance dualism is not based on such radically different metaphysical grounds that things which are intelligible to hylomorphic dualists are simply inaccessible to substance dualists. I, as a substance dualist, admit all the famous scholastic distinctions and at least think I understand most of them. That includes the four causes, the distinction between essence and existence, matter and form, substance and accident, act and potency, nature and suppositum, etc.
-Descartes was not such a novel break from the past. There have been many great philosophers throughout history prior to Descartes who have held substance dualist views. Think, for instance, of Plato, Plotinus, and St. Augustine, as well as Avicenna with his Floating Man argument.
-Descartes' substance dualism was not such a radical break from scholasticism. Though Aquinas almost certainly was the exemplar of hylomorphic dualism as I've defined it, scholasticism does not equal Aquinas (even if he was certainly one of the greatest scholastics). In Ockham for instance we see the body as being able to exist apart from the soul, at least if God wills it. In Buridan the soul is viewed more like a force pervading the whole body. Later in Suarez the soul and the body are each conceived as separable substances, albeit "incomplete" ones when taken alone. So in fact the path from them to Descartes is rather continuous, and we can see this insofar as Descartes continues to use scholastic terminology and makes use of the distinctions he received from Suarez. Again, all these people accepted the broadly Aristotelian metaphysical framework of scholasticism, and yet they were not all hylomorphic dualists as I've defined it above. So I think one can remain broadly scholastic without being a hylomorphic dualist (I'll say more about this last point--on the consistency of my generally scholastic views--in a later post).
-As regards the downfall of western civilization, Descartes was a devout and orthodox Catholic, and probably even converted the Queen of Sweden. So it is likely he did not do this terrible thing. More importantly though, as of now I have found nothing in substance dualism as I've defined it which is repugnant to the Catholic faith or heretical or implies something heretical, so this charge is simply unfounded.