NUMBER IS NOT IN QUANTITY; BUT QUANTITY IS IN NUMBER.
Why should these numbers be considered quantities? Doubtless because they are measures. But are these measures quantities, or quantity itself? As they are in the order of beings, even if they should not apply to any of the other things, the numbers will nevertheless remain what they are, and they will be found in quantity. Indeed, their unity designates an object, since it applies to another; then the number expresses how many objects there are, and the soul makes use of number to measure plurality. Now, when measuring thus, the soul does not measure the "whatness" (or, quality) of the object, since she says "one," "two," whatever be their objects, even if of opposite nature; she does not determine the character of each thing, for instance, if it be warm or beautiful; she limits herself to estimating its quantity. Consequently, whether we take Number in itself, or in the objects which participate therein, quantity exists not in these objects, but in the number; quantity finds itself not in the object three feet long, but in the number three.