He concludes as follows that nothing is: if [something] is, either what-is is or what-is-not [is], or both what-is and what-is-not are. But it is the case neither that what-is is, as he will show, nor that what-is-not is, as he will justify, nor that both what-is and what-is-not are, as he will teach this too. Therefore, it is not the case that anything is. And in fact, what-is-not is not. For if what-is-not is, it will be and not be at the same time. For in that it is considered as not being, it will not be, but in that it is not being, on the other hand, it will be. But it is completely absurd that something be and not be at the same time. Therefore, it is not the case that what-is-not is. And differently: if what-is-not is, what-is will not be, since they are opposites, and if being is an attribute of what-is-not, not-being will be an attribute of what-is. But it is certainly not the case that what-is is not, and so neither will what-is-not be. Further, neither is it the case that what-is is. For if what-is is, it is either eternal or generated or eternal and generated at the same time. But it is neither eternal nor generated nor both, as we will show. Therefore it is not the case that what-is is. For if what-is is eternal (we must begin at this point), it does not have any beginning. For everything that comes to be has some beginning, but what is eternal, being ungenerated, did not have a beginning. But if it does not have a beginning, it is unlimited, and if it is unlimited it is nowhere. For if it is anywhere, that in which it is is different from it, and so what-is will no longer be unlimited, since it is enclosed in something. For what encloses is larger than what is enclosed, but nothing is larger than what is unlimited, and so what is unlimited is not anywhere. Further, it is not enclosed in itself, either. For “that in which” and “that in it” will be the same, and what-is will become two, place and body (for “that in which” is place, and “that in it” is body). But this is absurd, so what-is is not in itself, either. And so, if what-is is eternal, it is unlimited, but if it is unlimited it is nowhere, and if it is nowhere it is not. So if what-is is eternal, it is not at all. Further, what-is cannot be generated either. For if it has come to be it did so either from a thing that is or from a thing that is not. But it has come be neither from what-is (for if it is a thing that is, it has not come to be, but already has), nor from what-is-not (for what-is-not cannot generate anything, since what generates anything must of necessity share in existence). Therefore, it is not the case that what-is is generated either. In the same ways, it is not both eternal and generated at the same time. For these exclude one another, and if what-is is eternal it has not come to be, and if it has come to be it is not eternal. So if what-is is neither eternal nor generated nor both together, what-is would not be. And differently, if it is, it is either one or many. But it is neither one nor many, as will be shown. Therefore it is not the case that what-is is. For if it is one, it is either a quantity or continuous or a magnitude or a body. But whichever of these it is, it is not one, but being a quantity, it will be divided, and if it is continuous it will be cut. Similarly if conceived as a magnitude it will not be indivisible. And if it chances to be a body, it will be three-dimensional, for it will have length, width and depth. But it is absurd to say that what-is is none of these. Therefore, it is not the case that what-is is one. Further, it is not many. For if it is not one, it is not many either. For the many is a compound of individual ones, and s since [the thesis that what-is is] one is refuted, [the thesis that what-is is] many is refuted along with it. But it is altogether clear from this that neither what-is nor what-is-not is. It is easy to conclude that neither is it the case that both of them are, what-is and what-is-not. For if what-is-not is and what-is is, then what-is-not will be the same as what-is as regards being. And for this reason neither of them is. For it is agreed that what-is-not is not, and what-is has been shown to be the same as this. So it too will not be. However, if what-is is the same as what-is-not, it is not possible for both to be. For if both [are], then they are not the same, and if [they are] the same, then [it is] not [the case that] both [are]. It follows that nothing is. For if neither what-is is nor what-is-not nor both, and nothing aside from these is conceived of, nothing is.
Sextus Empiricus on Gorgias, Against the Mathematicians