if two results are [5] the same their antecedents are also the same. For instance, it was a saying of Xenophanes that to assert that the gods had birth is as impious as to say that they die; the consequence of both statements is that there is a time when the gods do not exist.3 This line of proof assumes generally that the result of any given thing is always the same: e.g. ‘you are going to decide not about Isocrates, but about [10] the value of the whole profession of philosophy.’4 Or, ‘to give