Maria Plaza sets out to analyse the function of humour in the Roman satirists Horace, Persius, and Juvenal. Her starting point is that satire is driven by two motives, which are to a certain extent opposed: to display humour, and to promote a serious moral message. She argues that, while the Roman satirist needs humour for his work''s aesthetic merit, his proposed message suffers from the ambivalence that humour brings with it. Her analysis shows that this paradox isnot only socio-ideological but also aesthetic, forming the ground for the curious, hybrid nature of Roman satire.