 Historically, at least, it is likely that Aristotle is responding to an argument originating with the Megarian philosophers. He ascribes the view that only that which happens is possible to the Megarians in Metaphysics IX (Θ). The puzzle with which he is concerned strongly recalls the “Master Argument” of  Diodorus Cronus  especially in certain further details. For instance, Aristotle imagines the statement about tomorrow’s sea battle having been uttered ten thousand years ago. If it was true, then its truth was a fact about the past; if the past is now unchangeable, then so is the truth value of that past utterance. This recalls the Master Argument’s premise that “what is past is necessary”. Diodorus Cronus was active a little after Aristotle, and he was certainly influenced by Megarian views, whether or not it is correct to call him a Megarian (David Sedley 1977 argues that he was instead a member of the  Dialectical School  which was in any event an offshoot of the Megarians; see Dorion 1995 and Döring 1989, Ebert 2008 and the article Dialectical School). It is therefore likely that Aristotle’s target here is some Megarian argument, perhaps a forerunner of Diodorus’ Master Argument.