Why is Judas repeatedly contrasted in the Fourth Gospel with other characters, and why is he repeatedly depicted in these comparisons as the consummate defector? The answer to these questions, Martin argues, lies in the ancient rhetorical theory and practice of 'syncrisis', the formal, rhetorical comparison of persons or things. Surveying the Graeco-Roman textbooks of composition that taught this device and the ancient authors who used it, Martin shows that syncrisis was often used to juxtapose 'genera' or 'groups' via their 'outstanding' or 'extreme' members. In such comparisons, a two-level drama unfolds, with the verdict of superiority being applicable both to the individuals being compared and to the groups they represent. The Johannine Judas, Martin argues, is featured in this manner of comparison over against Peter, and his portrayal in the Gospel as the consummate defector points, along with several other clues, to his identity as a representative of the schismatics who seceded from the Johannine community and who are described in 1, 2 and 3 John.