The Summary of Physics Restored

46Corruption is far closer to being a principle of generation than privation, since it is a motion disposing matter for generation through successive degrees of alteration. Privation does nothing and carries out nothing in the work of generation, whereas corruption advances and prepares matter to make it capable of receiving form. Like a go-between it acts as a procurer, so that matter may more readily satisfy nature's lust and with its aid attain coupling with form. Corruption is therefore an instrumental and necessary cause of generation. Privation, however, is nothing other than the mere lack of an active and formal principle, and darkness upon the face of the abyss, namely formless and dark matter.