 It has been disputed whether the topos (or, more precisely, the ‘if …, then …’ scheme that is included in a topos) that we use to construe an argument must itself be regarded as a further premise of the argument. It could be either, as some say, the premise of a propositional scheme such as the modus ponens, or, as others assume, as the conditional premise of a hypothetical syllogism. Aristotle himself does not favour one of these interpretations explicitly. But even if he regarded the topoi as additional premises in a dialectical or rhetorical argument, it is beyond any doubt that he did not use them as premises that must be explicitly mentioned or even approved by the opponent or audience.