  On some other issues, the oppositions remain strong between the two masters. We have already seen that on the question of the status of the category of quantity, then at the border of logic and physics, Albert followed Ockham and distanced himself from Buridan by reducing quantity to a disposition of substance or quality. This move becomes evident in certain physical questions, e.g., in the study of condensation and rarefaction, where Albert openly disagrees with Buridan by arguing that condensation and rarefaction are possible only through the local motion of the parts of a body, and without needing to assume some quantity that would have a distinct reality on its own. Nevertheless, he defines the concept of a “lump of matter [materie massa]” without giving it any autonomous reality, although it does help fill out the idea of a ‘quantity of matter’, which Giles of Rome had already distinguished from simple extension.