There is a short section in Turretin’s Institutes I want to share with you. It is found in his section on Theology under the question, “Whether there is a theology and what are its divisions?” His fourth section under this broad heading distinguishes Metaphysics from Theology and is thus important for readers here. Turretin writes:
“Metaphysics is the highest of all sciences in the natural order, but acknowledges the superiority of theology in the supernatural order. The expression of philosophers – that sciences are distinguished by their greater or lesser abstraction and therefore the science which has least to do with matter as metaphysics is superior to all – must be understood of sciences merely theoretical, occupied with universal things only and belonging to the natural order. For these form their own objects by an abstraction of the mind, and their superiority is regulated by the degree of abstraction. However, this cannot apply to theology, being partly theoretical and partly practical and therefore superior to all in the natural order and not forming its own object by any abstraction, but receiving it from revelation already formed and distinct.” (Pg. 4, Q. II, Sect. IV)
It seems that Turretin is drawing this section directly from Thomas’s Metaphysics where he makes the same exact argument. According to Thomas, sciences are to be distinguished according to their “tethered-ness” to matter. Thus physics is less abstract than mathematics and mathematics is less abstract than metaphysics. Mathematics considers quantity in abstraction, whereas Metaphysics simply considers the concept of “existence” or “being” in abstraction and what can be drawn from it. Analogously, Thomas also argues that Metaphysics is a “higher” or better science because it corresponds to our “rational” or abstract nature – it is the greatest of all sciences because it is to the greatest degree intellectual.
Here Turretin agrees that, according to the “natural” order, proceeding from the light of man’s rational nature, metaphysics is the highest of all sciences. Granted Turretin proceeds with Thomas, man can deduce from the mere fact of existence the necessity of God and eternality. Yet Turretin makes a crucial distinction here: Metaphysics is the highest science according to it’s natural order (in other words, it proceeds from the mind of rational man according to abstraction). Theology, on the other hand, is the highest of all sciences because it proceeds according to a supernatural order, not dependent on abstraction but receiving it’s matter from revelation already formed and distinct. In other words, though Theology treats of matters abstract and practical (God and things), it is always of a higher order because it proceeds from the mouth of God himself and is endowed with His glorious mark, being formed not by man’s ability to abstract principally, but already formed from the mind of God. This, coupled with the fact that Theology deals with matters abstract and matters practical, through it’s unified goal of knowing God means that it is therefore superior to Metaphysics.