  The non-polemical anti-eternalist treatises exploit, among others, Aristotle’s argument that an infinite power (dúnamis) cannot reside in a finite body (Phys. VIII 10). Philoponus infers that since the universe is a finite body, it cannot have the dúnamis to exist for an infinite time. As in the case of his theory of light, this argument involves a not at all un-Aristotelian shift of meaning of the argument’s central concept. There, enérgeia shifted from ‘actuality’ to ‘activity’; in the context of Aristotle’s argument in Phys. VIII 10, dúnamis meant ‘power or kinetic force’, but Philoponus employs the word in the sense of ‘capacity’ or ‘fitness to exist’.