He writes: For the subject or substratum is differentiated by being a 'this' or not being one; i.e., the substratum of modifications is, e.g., a man, i.e. a body and a soul, while the modification is 'musical' or 'pale'.??? Wherever this is so, then, the ultimate subject is a substance; but when this is not so but the predicate is a form and a 'this', the ultimate subject is matter and material s