The standard interpretation of this passage sees Aristotle as claiming that if a thing is F eternally, its being F is not the exercise of any potentiality to be F, and as explicitly applying this claim to the heavenly bodies. This interpretation faces a number of difficulties: I shall offer a different reading which avoids these, and which brings out interesting connections between this passage and some arguments in Λ.6-7.

This paper examines Aristotle's discussion of the priority of actuality to potentiality in geometry at Metaphysics Θ9, 1051a21–33. Many scholars have assumed what I call the "geometrical construction" interpretation, according to which his point here concerns the relation between an inquirer's thinking and a geometrical figure. In contrast, I defend what I call the "geometrical analysis" interpretation, according to which it concerns the asymmetrical relation between geometrical propositions in which one is proved by means of the other. His argument as (...) so construed is ultimately based on the asymmetrical relation between the corresponding geometrical facts. Then I explore this ontological priority in geometry by drawing attention to a parallel passage, Posterior Analytics II.11, 94a24–35, where Aristotle explains the relation between the same geometrical propositions in connection to material causation. (shrink)

Aristotle’s soul is a first principle (an ‘efficient cause’) of every vital change in an animal, in the way that a craft is a cause of its product’s coming-to-be. We argue that the soul’s causal efficacy cannot therefore be reduced to the formal constitution of vital phenomena, or to discrete interventions into independently constituted processes, but involves the exercise of vital powers. This reading does better justice to Aristotle’s conception of craft as a rational productive disposition; and it captures the (...) soul’s continuous causal role as that which brings about all forms of vital change and underwrites their unity. (shrink)