Full Idea
Each thing that has a function is for the sake of that function.
Clarification
'Function' is the Greek word 'ergon'
Gist of Idea
Each thing that has a function is for the sake of that function
Source
Aristotle (On the Heavens [c.336 BCE], 286a08)
Book Reference
Aristotle: 'On the Heavens I and II', ed/tr. Leggatt,Stuart [Aris and Phillips 1995], p.121
A Reaction
This is the central idea of Aristotle's Ethics. Did it originate with Plato, or Socrates, the young pupil Aristotle? I suspect the strong influence of Aristotle on later Plato. A major idea. Functions link the facts to life.