Plato's Interpersonal Love in Diotima

Socrates and some young interlocutors try to define something in the lysis. Socrates decides that all friendship is based on a love for some kind of good. If i am your friend, it must be because of your goodness, says socrates. This is an idea about friendship that will be seeing again when we get to aristotle's nicomachian ethics. As usual, plato does seem to be showing an interest in interpersonal love.