Another favorite Aristotelian antithesis is that of Power and Act (δύναμις, ἐνέργεια). This distinction is made the basis of most of the physical philosophy of the school; being, however, generally introduced with a peculiar limitation. Thus, Light is defined to be “the Act of what is lucid, as being lucid. And if,” it is added, “the lucid be so in power but not in act, we have darkness.” The reason of the limitation, “as being lucid,” is, that a lucid body may act in other ways; thus a torch may move as well as shine, but its moving is not its act as being a lucid body.
Aristotle appears to be well satisfied with this explanation, for he goes on to say, “Thus light is not Fire, nor any body whatever, or the emanation of any body (for that would be a kind of body), but it is the presence of something like Fire in the body; it is, however, impossible that two bodies should exist in the same place, so that it is not a body;” and this reasoning appears to leave him more satisfied with his doctrine, that Light is an Energy or Act.
But we have a more distinctly technical form given to this notion. Aristotle introduced a word formed by himself to express the act which is thus opposed to inactive power: this is the celebrated word ἐντελέχεια. Thus the noted definition of Motion in the third book of the Physics,[33] is that it is “the Entelechy, or Act, of a movable body in respect of being movable;” and the definition of the Soul is[34] that it is “the Entelechy of a natural body which has life by reason of its power.” This word has been variously translated by the followers of Aristotle, and some of them have declared it untranslatable. Act and Action are held to be inadequate substitutes; the very act, ipse cursus actionis, is employed by some; primus actus is employed by many, but another school use primus actus of a non-operating form. Budæus uses efficacia. Cicero[35] translates it “quasi quandam continuatam motionem, et perennem;” but this paraphrase, though it may [75] fall in with the description of the soul, which is the subject with which Cicero is concerned, does not appear to agree with the general applications of the term. Hermolaus Barbarus is said to have been so much oppressed with this difficulty of translation, that he consulted the evil spirit by night, entreating to be supplied with a more common and familiar substitute for this word: the mocking fiend, however, suggested only a word equally obscure, and the translator, discontented with this, invented for himself the word perfectihabia.
[33] Phys. iii. 1.
[34] De Animâ, ii. 1.
[35] Tusc. i. 10.
We need not here notice the endless apparatus of technicalities which was, in later days, introduced into the Aristotelian philosophy; but we may remark, that their long continuance and extensive use show us how powerful technical phraseology is, for the perpetuation either of truth or error. The Aristotelian terms, and the metaphysical views which they tend to preserve, are not yet extinct among us. In a very recent age of our literature it was thought a worthy employment by some of the greatest writers of the day, to attempt to expel this system of technicalities by ridicule.
“Crambe regretted extremely that substantial forms, a race of harmless beings, which had lasted for many years, and afforded a comfortable subsistence to many poor philosophers, should now be hunted down like so many wolves, without a possibility of retreat. He considered that it had gone much harder with them than with essences, which had retired from the schools into the apothecaries’ shops, where some of them had been advanced to the degree of quintessences.”[36]
[36] Martinus Scriblerus, cap. vii.
We must now say a few words on the technical terms which others of the Greek philosophical sects introduced.