Socrates said this after his first speech when I believe Phaedrus is just starting to "fall under the spell" that Socrates is attempting to blind him with. Speak without fear (465) Phaedrus says to Socrates just a moment before Socrates, I my opinion gives a little more information than he wants to, so early in the text. The quote on page 465 was also very strong because it was unexpected by I think both Socrates and Phaedrus. .
Socrates is very adamant about madness, and how it is necessary. Necessary for all aspects of life, not just academic, rhetorical or philosophical but for something as fundamental as happiness. .
We, on our part, must prove that such madness is given by the gods for our greatest happiness; and our proof will not be accepted by the merely clever, but will accepted by the truly wise (469). .
It is my intention with this quote to show the crucial relationship between madness and the evolution of higher thought. I argue very plainly for this correlation linking the "truly wise" and madness because it demonstrates Socrates attempt to "dangle" an idea in front of Phaedrus, who after Socrates 1st speech was expecting a philosophical, structured way of defining the soul and now left to wonder what madness has to do with anything. The quote defends the claim that madness is an essential part of Socrates attempt to persuade Phaedus (the reader) that madness is not something bad; the way Lysias outlined it in his speech, but an obligatory element in developing a passion for something. .
My discourse has shown that this is, of all inspirations, the best and of the highest origin to him who has it or who shares in this madness, is called a lover (483). .
Taken from Socrates 2nd speech, Socrates is using madness now on a different level, this time as tool to describe inspiration to be a lover. Socrates literally cites his entire speech to explain how madness leads to love; to passion, not just an evolution of thinking, but also a pursuit of how it manifests itself through madness.