Jowett summary, Plato's "Symposium"
But Love desires the beautiful; and then arises the question, What does he desire of the beautiful? He desires, of course, the possession of the beautiful;—but what is given by that? For the beautiful let us substitute the good, and we have no difficulty in seeing the possession of the good to be happiness, and Love to be the desire of happiness, although the meaning of the word has been too often confined to one kind of love. And Love desires not only the good, but the everlasting possession of the good. Why then is there all this flutter and excitement about love? Because all men and women at a certain age are desirous of bringing to the birth. And love is not of beauty only, but of birth in beauty; this is the principle of immortality in a mortal creature. When beauty approaches, then the conceiving power is benign and diffuse; when foulness, she is averted and morose.
But why again does this extend not only to men but also to animals? Because they too have an instinct of immortality. Even in the same individual there is a perpetual succession as well of the parts of the material body as of the thoughts and desires of the mind; nay, even knowledge comes and goes. There is no sameness of existence, but the new mortality is always taking the place of the old. This is the reason why parents love their children—for the sake of immortality; and this is why men love the immortality of fame. For the creative soul creates not children, but conceptions of wisdom and virtue, such as poets and other creators have invented. And the noblest creations of all are those of legislators, in honour of whom temples have been raised. Who would not sooner have these children of the mind than the ordinary human ones? (Compare Bacon's Essays, 8:—'Certainly the best works and of greatest merit for the public have proceeded from the unmarried or childless men; which both in affection and means have married and endowed the public.')
I will now initiate you, she said, into the greater mysteries; for he who would proceed in due course should love first one fair form, and then many, and learn the connexion of them; and from beautiful bodies he should proceed to beautiful minds, and the beauty of laws and institutions, until he perceives that all beauty is of one kindred; and from institutions he should go on to the sciences, until at last the vision is revealed to him of a single science of universal beauty, and then he will behold the everlasting nature which is the cause of all, and will be near the end. In the contemplation of that supreme being of love he will be purified of earthly leaven, and will behold beauty, not with the bodily eye, but with the eye of the mind, and will bring forth true creations of virtue and wisdom, and be the friend of God and heir of immortality.
Such, Phaedrus, is the tale which I heard from the stranger of Mantinea, and which you may call the encomium of love, or what you please.