Initial Problem: Can a lover be a stable friend?
P1: The Lover is more dis-ordered than the non-lover.
P2: Love is a desire [Plato 237]
P2a: Erromenos Eros is the Supreme Desire.
P3: (Socrates speaking): The non-lover has all the advantages in which the lover is deficient.
P(1-3) establish that the lover is always unstable. He is concerned with pleasing the beloved. It seems if he is controlled by desire (Eros), then he isn’t rational. In fact, he is mad. But Socrates raises an interesting question: Do we not consider Eros divine (the ancient Greek would have said yes)? If so, he can’t be evil. If he isn’t evil, does that call into question P(1-3)? Socrates renews his argument:
P4: What if madness weren’t necessarily an evil? 
Prophecy is a kind of madness, yet no one considers prophets evil (not usually). Therefore, “love” might be a madness, but it isn’t automatically evil. Here Socrates breaks the narrative and talks about the nature of the soul. The soul is immortal, which means it is indestructible and self-moving. Therefore, the soul can’t be evil. Therefore, presumably, it’s desiring isn’t madness. In fact, it has to be mad.
P4*: Souls long for that which is beyond themselves .
Plato introduces the famous metaphor that the soul is a charioteer.
Soul = Good Horse (forms) OR Bad Horse (defective)
Problem: Truth is in the eternal realm, yet I am in this world of flux. How can I know truth? How can I know what I don’t yet know? Desire (Eros) mediates between what is known and what is unknown. As Socrates says, “I love, but know not what” . Thus, knowing is a form of loving. As Catherine Pickstock says, “Eros is described as a liquid, pouring into the eyes and overflowing into others” (Pickstock 239).
Pickstock suggests that knowledge implies a pre-understanding “through a desire to know.”