  But the author of §4, at any rate, insists that it is only because we have observed that moving things hereabouts, despite other differences, all share the property of moving through empty spaces, that we affirm that the same thing holds without exception in non-evident places too (xxxv 36–xxxvi 7). The full form of this sign-inference would therefore run: “Since moving things hereabouts all move through empty space, all moving things move through empty spaces; and since all moving things move through empty space, and there are moving things, there is such a thing as empty space”. But if assurance (diabebaiôsis) that the conclusion is true is produced in all cases by experience of similar cases (xxxvii 31–35), whether a sign is similar to what it signifies—as with the revelation that all human beings are mortal by their being so hereabouts—or it is not, as with movement’s being a sign of void (xxxi 1–7), then there will indeed be only one mode of sign-inference, and the EM, which does not proceed in this way, will be excluded.