also, those refutations that bring one to their conclusion through the consequent you should show up in the course of the argument itself. the mode in which consequences follow is twofold. for the argument either is that as the universal follows on its particular-as (e.g.) ‘animal’ follows from ‘man’-so does the particular on its universal: for the claim is made that if a is always found with b, then b also is always found with a. or else it proceeds by way of the opposites of the terms involved: for if a follows b, it is claimed that a’s opposite will follow b’s opposite. on this latter claim the argument of melissus also depends: for he claims that because that which has come to be has a beginning, that which has not come to be has none, so that if the heaven has not come to be, it is also eternal. but that is not so; for the sequence is vice versa.