THE STRANGE LOST DIALOGUE OF PLATO

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Socrates laughs heartily.

End of dialogue.

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If anyone knows of a dialogue where this happens at the very end, please notify me.

Could it be the Symposium / The Banquet? I think in that piece he is a minor figure.

Or could this be a lost dialogue of Socrates instead of Plato, in which Plato laughs heartily?

Perhaps it is called Sophrosyne, and features the idea that Plato is a valuable student...