Development Of The Human Soul

Appendix 2. (797).

St. Thomas says more or less the same. 'You must know that corporeal substance has what makes it the subject of accidents because of its matter WHOSE FIRST CHARACTERISTIC IS TO BE PRESENT IN SOMETHING ELSE AS SUBJECT TO IT' (hence matter is also the subject of substantial form). 'But the first disposition of matter is QUANTITY' (note that determined quantity does not pertain to matter, but is a disposition coming from elsewhere; indetermined quantity, that is, quantity in potency to determination, is essential to the concept of matter) 'because the division or lack of division in matter depends on gether with unity and multitude which are its first consequences. Dispositions of the whole of matter, but not particular dispositions, are another consequence of this' (indetermined continuous quantity and the unity of the continuum is an essential constitutive of matter. This is not the case with discrete quantity, that is, with multiplicity, which is essential only in potency in so far as the continuum can always be thought as divided into further continua).

'Hence all other accidents are founded in substance THROUGH QUANTITY WHICH IS NATURALLY PRIOR TO THEM. Quantity, therefore, does not include sensible matter in its concept, although it does include intelligible matter, as we find in VII Metaphysicorum.' Sensible matter means matter in potency to sensible qualities; intelligible matter means matter conceived abstractly without reference to sensible qualities. It affirms that the definition of quantity presupposes matter as its subject; it does not affirm that we need think of this matter as subject of such qualities which are thought of after the abstract quantity. Indeed, quantity itself, when determined, is the subject of such qualities. This enables us to confute Descartes' error. For him, the substance of bodies lies in extension, a mistake already made by several Scholastics: 'Some have erred, and were led to believe that dimensions were the substance of material things because they saw nothing sensible remaining after the removal of the qualities except quantity which, however, according to its being, depends on substance in the same way as other accidents' (In IV Sententiarum, d. 12, q. 1, art. 1).