The 5 most important things that Diotima tried to teach Socrates about love were that:
- Socrates was wrong in saying that if Love desired x, Love must not have x. For example, if Love desires beauty, Love cannot be beautiful. Rather, Diotima says that desire of something does not necessarily mean complete lack of that thing. She posits that Love is the mean between 2 extremes, such as the mean between wisdom and ignorance, and explains this through the story of its birth. In this way, Love can both be beautiful and yet desire beauty.
- Love means wanting to possess the good forever, and that is why we pursue Love with such eagerness and zeal.
- The true kind of Love is achieved through pursuing the good, but there is a slight perversion of Love that occurs when people pursue happiness through indirect means, such as money or fame.
- Love gives birth to beauty. In a way, reproduction leads to immortality, and in the act of reproduction/pregnancy, the parents become more joyful and more beautiful - more good. So, reproduction is the act that allows Love to possess the good forever.
- Love must desire immortality.
I think that Alcibiades is only pretending to be drunk, because it seems to be his primary goal to get Socrates drunk. I don't really know what their relationship is at this point, but perhaps he thinks if Socrates is drunk, he will be more loose with Alcibiades, though he mentions bitterly that no matter how much he drinks, Socrates will not become drunk. I've never been drunk before, so I can't say for sure, but it seems to me that he is wayyyyyy too articulate to be drunk as well. That factor aside, I think other things point to his sobriety as well - perhaps he is only pretending to be drunk so that they will let him into the party in an attempt to calm him down. He seems to be angry about Socrates sitting next to Agathon, so it seems possible that he came to break up the Love party and make sure that Socrates was being faithful to him, and just used the guise of being drunk to be allowed in.