Everyone congratulates Socrates at the conclusion of his speech, when they are suddenly interrupted by loud knocking at the front door. Soon thereafter, Alcibiades bursts in, drunk, supported by a flute-girl, surrounded by a few other revelers, and wearing a thick garland of ivy, violets, and ribbons. Alcibiades asks if he might join the symposium even though he is very drunk, or if he should just do what he has come to do--to wreath the victorious Agathon with his garlands--and go away again. The company urges Alcibiades to stay, and so he stumbles on to the couch next to Agathon, displacing Socrates.
When Alcibiades notices Socrates, he cries out, protesting that Socrates has been sharing a couch with Agathon, the most attractive man in the room. Socrates asks for Agathon's protection, pointing out that ever since he began loving Alcibiades, Alcibiades has been so jealous of him that he cannot stand it when Socrates comes near another attractive man.
Alcibiades then unties some of Agathon's garlands, placing them on Socrates, since Socrates always beats everyone in verbal contest, while Agathon has only been victorious once, with his recent tragedy. Next, he takes charge of the revels, electing himself master of ceremonies, and insisting that everyone get drunk. He quickly downs four pints of wine, and insists that Socrates do the same, though he observes that alcohol never has any effect on Socrates.
Eryximachus demands that Alcibiades take part in the symposium and give his own speech in praise of Love. Alcibiades complains that this would be unfair, as he has already drunk far too much. Besides, Socrates would get jealous if he were to praise anyone other than Socrates in Socrates' presence. Thus, with Eryximachus' permission, he undertakes to deliver a eulogy to Socrates.
Alcibiades claims that Socrates is like a satyr, both in appearance and in other ways as well. Marsyas, the flute-playing satyr, could produce bewitching flute-music with the power of his mouth. Socrates, Alcibiades suggests, can also bewitch people with his mouth, though he needs no flute, using words alone. Unlike any other orator, Socrates has made Alcibiades dissatisfied with his way of life, convincing him that in following politics he neglects himself. Further, Socrates is the only person who has ever made Alcibiades experience shame. Whenever Socrates speaks to him, he cannot argue with anything Socrates says. But when Socrates leaves he gets caught up in the admiration of others and ignores Socrates' wisdom so that when next he sees Socrates he is once more ashamed.
Alcibiades, in his sudden and unexpected appearance, stands as a thinly veiled symbol for the god Dionysus himself. Alcibiades appears garlanded, young, beautiful, and drunk, much the way Dionysus is often depicted. He is coming in from a street-party, and is accompanied by many revelers, just as Dionysus is frequently accompanied by his Bacchae. Further, Alcibiades urges the guests to drink, and Dionysus is the god of wine.