Ἀρχή

[The] principles of the universe [are] two: the active and the passive.¹ The active² is the reason in matter, i.e. god. The passive,³ then, is unqualified substance, i.e. matter. Principles and elements are different. For while the former are ungenerated and indestructible, the latter are destroyed in the conflagration.⁴ But the principles are incorporeal⁵ and without form, whereas the elements are endowed with form.