The ontological status of these does not concern him, but we may suppose that they consitute the category of quantities: the bodies, surfaces, edges, corners, places, and times, sounds, etc. of physical substances (Categories 6).
The category of quantity, therefore, does not admit of variation of degree.
Strictly speaking, only the things which I have mentioned belong to the category of quantity: everything else that is called quantitative is a quantity in a secondary sense.
Moreover, why does Aristotle include speech as a species in the category of quantity?
In particular, we do not need them in the category of quantity.
He claims, strikingly, that the category of quality flows from form and that the category of quantity flows from matter.
So, a second question about Aristotle's category of quantity naturally suggests itself: how can body be a species in both the category of quantity and the category of substance?
Some scholars have proposed that a universal science of 'posology' (a science of quantity) takes the whole category of quantity as its subject.
As discussed in the next section, the category of quantity and the language of measuring occupied a central place in Lefèvre's approach to Aristotle's natural philosophy.
If the highest genus of the category of quantity is a form, the seven species Aristotle enumerates (line, surface, solid, time, place, number, and speech) clearly are not.
Aristotle's list of species in the Category of Quantity is thus not merely puzzling but seems to commit Aristotle to a contradiction.
