Diese Metapher wurde so nicht in einem Text von 
Aristoteles überliefert, sondern durch den antiken Philosophiehistoriker 
Diogenes Laertios, der sechs Jahrhunderte nach Aristoteles an einem unbekannten Ort gelebt hat.
Aristoteles, nach Diogenes Laertius:
 
- 
 " Ἐρωτηθεὶς τί ἐστι φίλος, ἔφη, 'Μία ψυχὴ δύο σώμασιν ἐνοικοῦσα.' "  
- "Die Frage: Was ist ein Freund? beantwortete er mit der Erklärung: 'Eine Seele, die in zwei Leibern wohnt.' "
 
 Diogenes Laertius: "Leben und Meinungen berühmter Philosophen." Übersetzt von Otto Apelt, Band 1, Verlag von Felix Meiner, Leipzig: 1921 V, Aristoteles, 20, S. 215 (Link)
-  20. To the query, "What is a friend?" his reply was, "A single 
soul dwelling in two bodies." Mankind, he used to say, were divided into
 those who were as thrifty as if they would live for ever, and those who
 were as extravagant as if they were going to die the next day. When 
some one inquired why we spend much time with the beautiful, "That," he 
said, "is a blind man's question." When asked what advantage he had ever
 gained from philosophy, he replied, "This, that I do without being 
ordered what some are constrained to do by their fear of the law.
 
 Diogenes Laërtius: "Lives of the Eminent Philosophers", translated by Robert Drew Hicks, Book V, Aristotle 20  (Link)