This word originally came from Greek, but it developed through Latin and came into Middle English. The Greek word “entelekheia,” notably used by philosopher Aristotle, was the first iteration of “entelechy,” and came from a combination of the words “en” (“within”), “telos” (“end, perfection”), and “ekhein” (“be in a certain state”). Aristotle used it in relation to the achievement of potential, but “entelechy” is also used today in a biological sense. Animals that go through metamorphosis undergo multiple stages of development in order to reach entelechy. Frogs, for example, hatch as tadpoles and use a long flagellate tail to move around. As they metamorphosize, tadpoles eventually develop legs and realize entelechy as adult frogs.