Commentators have been misled into thinking that energeia is actuality, in part by a confusion about being-in-capacity. Too much emphasis has been placed on cases in which what is in capacity F is not yet F. There are such cases. However, being-in-capacity is, in the first instance, a way of being. What is in capacity F is F. It is not merely that it could become F. It already is — albeit merely in capacity. It turns out that, in limiting cases, being-in-capacity is compatible with not-being. This is important. It is a way of allowing for the compatibility of being and not-being, without breaking the law of noncontradiction. But it does not change the fact that being in capacity F is being F. I hesitate to say that what is in capacity F is actually F, because that might be taken to mean that what is in capacity F is fully, properly, and in the primary sense F — which would be incorrect. But one might well say that what is in capacity F is actually F, so long as that is taken to mean that what is in capacity F is already F, and is not merely such that it could become F . [I will defend this in my account of Theta 7 in Ch. 11.]

Despite all this, I do think that ‘actuality’ or ‘actually’ is sometimes the best translation for energeia. For instance, in Aristotle  ’s account of the infinite and perhaps in passages in which he equates energeia and form. But I think that this is so much less often than has generally been thought. For instance, I think that it is wrong to take Aristotle’s argument about the unmoved mover in Λ.6 as concluding that the essence of the unmoved mover is actuality. The translations ‘actuality’ (or ‘actually’) are dangerous, even — or rather, especially — in cases where the translation seems perfectly sensible.

To some extent, the translation ‘actuality’ is an accident of history. ‘Actuality’ is simply an English cognate of a perfectly sensible Latin translation, actualitas, derived from in actu (which translates energeiai or kat’ energeian). It is a holdover from the days in which English speakers who read Aristotle could be expected to know Latin, and to construe English translations in terms of their Latin roots. That is no longer the case. Moreover, now that ‘actuality’ has a life of its own in ordinary and philosophical English, it can no longer be used in that way.

This is also a reason not to use ‘actuality’ as a harmless placeholder for a term that has no good translation into English. It cannot be a harmless placeholder. That may have been possible before ‘actually’ became an ordinary English word. But, as a matter of fact, the translation ‘actuality’ continues to create serious problems even for careful readers of Aristotle.

But the enduring appeal of this translation is not a historical accident. It is very difficult to understand how energeia, if it is best translated ‘activity,’ could refer to a way of being. Not understanding how that could be, it has seemed easy and natural to fall back upon our word ‘actuality’ with its Aristotelian antecedents. I hope that the interpretation presented in this book has solved this difficulty. [BEER, Jonathan. Doing and Being. An Interpretation of Aristotle’s Metaphysics Theta. Oxford: Oxford University Press, 3009]