While Aristotle’s explicit focus in Metaphysics Theta 1-5 is dunamis in the sense of the ‘capability’ a thing has to originate change in something else or in itself qua other, practically all translators, when they arrive at chapter four, switch to ‘possible’ and ‘impossible’ as translations of dunaton and adunaton. Such a switch is neither defensible nor necessary and the relevance of Theta 4 is understood only without it.

Ancient Philosophy | History of Philosophy