4. What is the common element in these three things (matter, form and
their combination)? What constitutes their (sublunary, mundane or)
earthly "being"? Is it because matter, form and their combination
form a foundation for other things? In that case, as matter is the
foundation, or seat of form, then form will not be in the genus of
"being." But, as the combination also forms foundation for other
things, then form united to matter will be the subject of the
combinations, or rather, of all the things which are posterior to the
combination, as quantity, quality, and movement.