1.) Entelekia = in goal abiding = fixed in target
2.) In one sense entelekia is opposed to motion as fixity in target to what is going to it. In a subsequent sense, motion is nothing other than the potential fixity in the target, or entelekia in potency as potency.
3.) Entelekia is first is being but not first in time. The primacy in being is proportionate to its primacy in causality. Ultimately, existence is the principle both of intelligibility and causality.
4.) A person’s primary ontology or account of existence concerns what he believes about the relation between causality and time. In the Platonic and Aristotelian traditions what is first in time is last in causality, and so all physical actions ultimately have only hypothetical necessity from an agent capable of acting for future goals, though the action of this agent generates a subsequent physical determinism. Again, the fixity and predictability of physical action is entirely subsequent to the fixity of the fixity of an agent’s goals.
Physicalism or Naturalism* takes this physical determination as ultimate (it makes no difference if this determination is from an absolute or only probable law so long as one denies ultimate causal primacy to entelekia). In Platonic-Aristotelian lingo, the “causal closure of the physical” is nothing but the claim that what is first in causality, and therefore first in being, is first in time; or that physical determination is primary and not subsequent to the intentional causality of entelekia.
Because of the interrelation of physical actions, the question of the entelekia of all of them was either intractable or too general to be useful. We could know that there was some agent acting for future goals, but we had no way of knowing exactly what these future goals were except to the extent that (a) our own intentions gave us some insight into the agent’s or (b) the agent himself told us.
For all that, there was a cheerier story about our own causality: to the extent that things anticipate the future and/or formulate intentional goals, they have access to the fount of physical causality. This allows them to construct physical histories of their own. Since physical action as such is subsequent to intentional action, there is no causal closure of the physical either eliminating the action of divinity or any other intelligence on causal physical histories.
5.) To the extent that we undermine the the primacy of entelekia nature becomes at once utterly determined and purely by chance, and we predict the future as surely as an eclipse from an initial condition that is purely unintelligible from the law itself.
*Or, in the ancient world, the wildly popular philosophy of Epicureanism.