Energeia and Entelecheia: "Act" in Aristotle

Jiyuan Yu, a lecturer in the Philosophy Department at the People’s
University of China, is a visiting scholar at the University of Guelph.

Scholars generally agree that though energeia and entelecheia are
different etymologically, Aristotle uses them interchangeably. Both of
them share the same two meanings. One meaning is dynamical, with
reference to motion (translated normally as “activity”); another is
static, with reference to substance (translated as “actuality” or
“actualization”). Blair finds this traditional position puzzling and
argues that it is incomprehensible for Aristotle to coin two words and
then give each the same meanings. He claims that energeia is dynamical
exclusively, while entelecheia is static exclusively.

This is obviously a hard thesis to defend. Blair claims that
entelecheia must be rendered as “having the end within.” But in
Physics III, motion is defined as the entelecheia of the potential as
such. To cope with that, Blair appeals to the extreme genetic method by
taking the Physics passage as earlier and immature and asserting that it
is revised in Metaphysics XI in which motion is defined as energeia. He
insists that energeia must always be translated as “internal
activity.” However, energeia is always associated with ousia and
eidos, and the latter two are normally conceived in the static sense.
But Blair argues that ousia as reality could mean “to live,” while
eidos should be translated as “aspect” rather than “form.” The
approach sounds very similar to what Heidegger has done with Greek
philosophy, which, though interesting in itself, has not won general
acceptance.

Even so, there are too many passages to be explained away. Blair is
forced to say that these two words are different “in the sense of what
the word is saying” but the same “in the sense of what the words are
talking about,” and that “entelecheia never means activity, but what
it always in fact is is an internal activity.” In other words, these
two words are different etymologically but are the same in application.
Clearly Blair’s final position is not far from the traditional one.

The book investigates in detail the etymology of the two words, and
conducts a valuable computer survey of the distribution of them that
will prove useful for researchers wishing to locate references.