Using examples from the late 19th century to the present, it will be discussed to what extent anti-Semitism was shaped by a »legal code«. The pressure of legal repression, however weak it may have been at times, caused anti-Semites to retreat to language formulas that were no longer (or not yet) legally objectionable, without therefore giving up their convictions. This borderline is fundamentally semantically indeterminable, because associations, puns and cynicism cannot be banned. The legal instruments often come to nothing, because a judiciary under the rule of law may only sanction deeds, not thoughts. Each judgement inevitably redefines this borderline, at least in nuances. By contributing in this way to constituting the discursive framework of anti-Semitism, even if there is a broad social consensus of its ostracism, the law is both a partial solution and part of the problem.