In this way, then, there were four opinions among philosophers concerning intensity and remission of habits and forms, as Simplicius relates in his Commentary on the Predicaments. For Plotinus and the other Platonists held that qualities and habits themselves were susceptible of more or less, for the reason that they were material and so had a certain want of definiteness, on account of the infinity of matter.  Others, on the contrary, held that qualities and habits of themselves were not susceptible of more or less; but that the things affected by them (qualia) are said to be more or less, in respect of the participation of the subject:  that, for instance, justice is not more or less, but the just thing.  Aristotle alludes to this opinion in the Predicaments (Categor. vi).  The third opinion was that of the Stoics, and lies between the two preceding opinions.  For they held that some habits are of themselves susceptible of more and less, for instance, the arts; and that some are not, as the virtues.  The fourth opinion was held by some who said that qualities and immaterial forms are not susceptible of more or less, but that material forms are.

In order that the truth in this matter be made clear, we must observe that [that], in respect of which a thing receives its species, must be something fixed and stationary, and as it were indivisible:  for whatever attains to that thing, is contained under the species, and whatever recedes from it more or less, belongs to another species, more or less perfect.  Wherefore, the Philosopher says (Metaph. viii, text. 10) that species of things are like numbers, in which addition or subtraction changes the species.  If, therefore, a form, or anything at all, receives its specific nature in respect of itself, or in respect of something belonging to it, it is necessary that, considered in itself, it be something of a definite nature, which can be neither more nor less.  Such are heat, whiteness or other like qualities which are not denominated from a relation to something else:  and much more so, substance, which is per se being.  But those things which receive their species from something to which they are related, can be diversified, in respect of themselves, according to more or less:  and nonetheless they remain in the same species, on account of the oneness of that to which they are related, and from which they receive their species.  For example, movement is in itself more intense or more remiss:  and yet it remains in the same species, on account of the oneness of the term by which it is specified.  We may observe the same thing in health; for a body attains to the nature of health, according as it has a disposition suitable to an animal’s nature, to which various dispositions may be suitable; which disposition is therefore variable as regards more or less, and withal the nature of health remains.  Whence the Philosopher says (Ethic. x, 2, 3):  “Health itself may be more or less:  for the measure is not the same in all, nor is it always the same in one individual; but down to a certain point it may decrease and still remain health.”