It must be understood that prime matter, and form as well, is neither generated nor corrupted, because every generation is from something to something. Now that from which generation proceeds is matter, and that to which it proceeds is form. So that, if matter or form were generated, there would be a matter for matter and a form for form, endlessly. Whence, there is generation only of the composite, properly speaking.
Joseph Bobik, Saint Thomas (Aquinas) (1998). “Aquinas on matter and form and the elements: a translation and interpretation of the De principiis naturae and the De mixtione elementorum of St. Thomas Aquinas”, Univ of Notre Dame Pr
