http://www.mc.maricopa.edu/~yount/te...to-ladder.html
Starting from individual beauties, the quest for the universal beauty must find him ever mounting the heavenly ladder, stepping from rung to rung--that is, from one to two, and from two to every lovely body, from bodily beauty to the beauty of institutions, from institutions to learning, and from learning in general to the special lore that pertains to nothing but the beautiful itself--until at last he comes to know what beauty is.
And if, my dear Socrates, Diotima went on, man's life is ever worth the living, it is when he has attained this vision of the very soul of beauty. And once you have seen it, you will never be seduced again by the charm of gold, of dress, of comely boys, or lads just ripening to manhood; you will care nothing for the beauties that used to take your breath away and kindle such a longing in you, and many others like you, Socrates, to be always at the side of the beloved and feasting your eyes upon him, so that you would be content, if it were possible, to deny yourself the grosser necessities of meat and drink, so long as you were with him.
But if it were given to man to gaze on beauty's very self--unsullied, unalloyed, and freed from the mortal taint that haunts the frailer loveliness of flesh and blood--if, I say, it were given to man to see the heavenly beauty face to face, would you call his, she asked me, an unenviable life, whose eyes had been opened to the vision, and who had gazed upon it in true contemplation until it had become his own forever?
And remember, she said, that it is when he looks upon beauty's visible presentment, and only then, that a man will be quickened with the true, and not the seeming, virtue--for it is virtue's self that quickens him, not virtue's semblance. And when he has brought forth and reared this perfect virtue, he shall be called the friend of god, and if ever it is given to man to put on immortality, it shall be given to him
(Plato - Symposium 210a-212b).