Scholars have observed that in Aristophanes’ Clouds entrance to the phrontisterion is likened to initiation into the mysteries; but there seems to have been no discussion of the effect that such a comparison would be likely to produce upon an audience of the period. In the present paper I wish to explore this question; and also to consider the relevance of Aristophanes’ words to anything Socrates may himself have said or done, and Plato’s attitude to the situation.