The curious production history of Clouds claimed scholarly attention already at the library in Alexandria. From an ancient hypothesis, we learn that the play failed miserably at its first performance at the Dionysia of 423. Dismayed at this reverse, the same source reports, and convinced that his audience had failed to appreciate the play's merits, Aristophanes undertook a revision in the hope of allowing them to correct their error. The play we have is the revised version, and in its parabasis Aristophanes comments on the circumstances that necessitated a second effort. Modern scholars have been eager to determine the nature, date and extent of Aristophanes' revisions for what they can tell us about the original play, only a few fragments of which survive. Our clearest insight into these problems is provided by another hypothesis (Hyp. I), which describes the second Clouds as “the same as the former” (τοῦτο ταὐτóν ἐστι τῷ προτέρῳ), but then goes on to describe changes affecting nearly every part of the play (καθóλου μὲν οὖν σχεδὸν παρὰ πᾶν μέρος γεγενημένη <ἡ> διóρθωσις), with some passages (parabasis, agon of the Arguments, finale) identified as entirely new to the revised play. While these considerations will affect the discussion at some points, by and large this study will concern itself with the original Clouds only to the extent necessary to understand the circumstances of the revision. Nor do I assume that our Clouds necessarily bears much resemblance to its predecessor.