Phi - Just Another Voiceless Labiodental Fricative

SOCRATES: And there is no difficulty in seeing the cause which renders any mixture either of the highest value or of none at all.

PROTARCHUS: What do you mean?

SOCRATES: Every man knows it.

PROTARCHUS: What?

SOCRATES: He knows that any want of measure and symmetry in any mixture whatever must always of necessity be fatal, both to the elements and to the mixture, which is then not a mixture, but only a confused medley which brings confusion on the possessor of it.

PROTARCHUS: Most true.

SOCRATES: And now the power of the good has retired into the region of the beautiful; for measure and symmetry are beauty and virtue all the world over.

PROTARCHUS: True.

SOCRATES: Also we said that truth was to form an element in the mixture.

PROTARCHUS: Certainly.

SOCRATES: Then, if we are not able to hunt the good with one idea only, with three we may catch our prey; Beauty, Symmetry, Truth are the three, and these taken together we may regard as the single cause of the mixture, and the mixture as being good by reason of the infusion of them.

PROTARCHUS: Quite right.

--Plato, "Philebus"