  Another important case is that in which principles are imported from another science to complete a demonstration. So if one proves that circular wounds heal more slowly because they have a large ratio of area to circumference, and healing proceeds at the edge of a wound, one has borrowed, in medicine, a principle from geometry. The physician (qua physician) need not know this principle (that is, he need not know the reason why it is so, so that he is able to prove it), but may rely on the authority of the geometer (without being open to criticism as a physician). In such a case the demonstration is said to be “subalternate” to another science, and the nature of this subalternation provided a subject for debate between more Augustinian and more Aristotelian commentators on Aristotle.