At this point, Diotima gives Socrates instruction on how to progress in the pursuit of beauty.
One who will rightly undertake this project must begin from youth to go after beautiful bodies, and first, if the leader [namely, Love] shows the way, to love one body, and with that person to beget fair conversations, and then to recognize that the beauty in one body is akin to that in another, and that if he is going to pursue the beauty of form, it would be mad not to consider that the beauty in all bodies is one and the same. And realizing this, he should make himself a lover of all bodies and despise and reject the excessive love of the individual. After this, he must consider the beauty in souls to be more valuable than that in the body … so that he will be compelled to behold the beauty in practices and customs, and to see that all this is akin, until he considers the beauty of the body to be insignificant.
After admiring practices, he will be led to the sciences, that he may see their beauty, and looking now on their great beauty, not of the individual, as a slave might look at the beauty of a boy or man, or a single practice—since he is a lowly servant and small-minded—but turned toward a vast sea of beauty and beholding many beautiful and magnificent theories, he begets thoughts in an abundant philosophy, until being strengthened and increased he catches sight of a single science, which is that of such beauty.
Diotima goes on to describe the character of Beauty:
First, it always is, and neither comes to be nor perishes, neither increases nor decreases; further, it is not beautiful in one way, ugly in another; nor beautiful and one time but not another; nor beautiful in relation to one thing, but ugly in relation to another; nor beautiful here, but ugly there, for instance beautiful to some, but ugly to others.[2]
She concludes with a kind of challenge:
Well what, [Diotima] said, do we think, if someone should happen to glimpse Beauty, immaculate, pure, undiluted, untainted by human flesh, colors, or any mortal corruption, but be able to observe the divine beauty in its simpicity? Do you think, she said, that a person would have a bad life gazing on that on which he ought to behold and with which he ought to live? Or don’t you think, she said, that in that way only it will be possible for him to see the Beautiful in the way it is visible, so as to beget, not images of virtue, because he is not in contact with images, but true virtue, because that is what he is in contact with? And by begetting virtue and being nourished by it, he will become dear to the gods and immortal if any man ever can be?
After this glimpse of a kind of beatific vision of Beauty, Socrates ends his speech and receives an ovation from his companions. Here, perhaps for the first time in the Platonic corpus, we see Plato’s passionate celebration of a kind of life in which humans can be in touch with the divine, along with a sketch of a world of ideal entities that objectify all that is good and noble in the world. These will be known as the Forms, of which Beauty is one. They are introduced here without argument or theoretical justification, in fact at a drinking party in which the wine is flowing freely and the other speeches range from the comical (Aristophanes’ speech) to the mildly serious.
Socrates himself does not here endorse what will emerge as the Theory of Forms, but he does share it as a teaching from an inspired woman, a prophetess from Mantinea. Plato publishes it for the consideration of his readers, in one of the least philosophical, or least methodical, of his dialogues.
[2] Plato Symposium 210a-211a.