According to Aristotle, the term “fulfilment” (entelexeia) signifies the agency and completion; for it is composed of the one, the complete, and the having, since each one thing is said to be in fulfilment when it has its own completion.
The fulfilment is twofold
Of each case the fulfilment is twofold: in one sense, when the actual thing is already done and its whole potentiality has been thrown away, in another, when it has been changed by the potency and is altering in accordance with it and coming to receive its form, as with the copper that is potentially a statue. For we regard it to be a case of fulfilment both when it becomes a statue by the sculptor and forms into such and such a shape, and when it is already a statue and has received its complete form.
But the latter fulfilment is exempt from the presence of the potency by virtue of which it was capable of becoming a statue — for it is already a statue and is no more in potentiality. That is why this fulfilment is not the completion of the potency (for how could it be, if it passes away?), but that of the actual thing where the potency was based in. On the other hand, the former mentioned fulfilment, by virtue of which the copper was coming to be a statue, still maintains its potentiality.
And this fulfilment is an incomplete agency (for it proceeds towards the form and the most spoken of and unqualified fulfilment) — and for that reason is called first fulfilment — whereas the other is a complete agency; for the thing changed rests within it when it comes to be whatever is the case, and relieves itself entirely of being in potentiality.
Bibliography: J. Philoponus in Aristotle’s Physics
Translation – text editing: George Kotsalis