course of the history of science that reference to the modern term is not very helpful in understanding the original as used by Aristotle. It is difficult to translate his use of into English with consistency. Joe Sachs renders it with the phrase "being–at–work" and says that "we might construct the word is-at-work-ness from Anglo-Saxon roots to translate into English". Aristotle says the word can be made clear by looking at examples rather than trying to find a definition. Two examples of in Aristotle's works are pleasure and happiness (eudaimonia). Pleasure is an of the human body and mind whereas happiness is more simply the of a human being a human. , translated as movement, motion, or in some contexts change, is also explained by Aristotle as a particular type of . See below. Entelechy () Entelechy, in Greek , was coined by Aristotle and transliterated in Latin as . According to : Aristotle invents the word by combining (, 'complete, full-grown') with (= hexis, to be a certain way by the continuing effort of holding on in that condition), while at the same time punning on (, 'persistence') by inserting telos (, 'completion'). This is a three-ring circus of a word, at the heart of everything in Aristotle's thinking, including the definition of motion. Sachs therefore proposed a complex neologism of his own, "being-at-work-staying-the-same". Another translation in recent years is "being-at-an-end" (which Sachs has also used). , as can be seen by its derivation, is a kind of completeness, whereas "the end and completion of any genuine being is its being-at-work" (). The is a continuous being-at-work () when something is doing its complete "work". For this reason, the meanings of the two words converge, and they both depend upon the idea that every thing's "thinghood" is a kind of work, or in other words a specific way of being in motion. All things that exist now, and not just potentially, are beings-at-work, and all of them have a tendency towards being-at-work in a particular way that would be their proper and "complete" way. Sachs explains the convergence of and as follows, and uses the word actuality to describe the overlap between them: Just as extends to because it is the activity which makes a thing what it is, extends to because it is the end or perfection which has being only in, through, and during activity. Motion Aristotle