A key passage in the development of Aristotle’s argument in book Θ of the Metaphysics is the distinction between the concepts of κίνησις and ἐνέργεια (1048b18-35).
The distinction is made initially on the basis of particular grammatical features of verbs denoting human actions/states: some verbs in the present tense necessarily imply the contemporaneous achievement of the same verb in the Greek perfect tense (e.g. If x is seeing y, then it is the case that, at the same time, x is in a state of having seen y), whereas other verbs in the present tense are necessarily followed by (i.e. do not occur simultaneously with) the same verb in the Greek perfect tense (e.g. If x is building y, then it is not the case that, at the same time, x is in the state of having built y). Aristotle concludes that the former type of verbs (ἐνέργεια-actions) are actions which contain their proximate (i.e. most immediate) end, whereas the latter type (κίνησις-actions) are actions whose proximate ends are separate, the attainment of which yields the termination of the action. The argument in the passage, therefore, circulates around the place of proximate ends within action.
This paper applies the key features of the κίνησις-ἐνέργεια distinction to Aristotle’s discussion of the δύναμις-ἐνέργεια analogy (1048a35-b9), and argues that, if Aristotle’s κίνησις-ἐνέργεια distinction is to be taken seriously, the analogy must be thought of primarily in terms of teleology. This result is finally applied to the problem of unattainable ultimate (i.e. remote) ends, or ends which human actions strive for but never reach. The problem (unsurprisingly) finds its solution in Aristotle’s natural theology presented in book Λ