The philosophical treatise of Melissus of Samos is often maintained to have a strictly deductive argumentative structure. This article attempts to confirm this thesis by establishing that such a structure is instituted beginning from its title and introductory sphragis. Extant paraphrases of Melissus’ treatise are examined and are argued (in line with some previous treatments) to provide a highly illuminating indication that the work began from the hypothesis that something is. Next, an account of how the first verbatim fragment (DK30B1) takes up this prefatory material is given along with a reconstructed text and translation of the title, preface and argument for the sempiternity of what-is.

Several lines of reasoning have been employed to both approve and disapprove two of Nicholas Agar’s positions: his argument that the creation of postpersons (based on moral status enhancement) is imaginable and possible and his inductive argument disfavoring the creation of postpersons. This article discusses a number of these lines of reasoning, arguing that

1. 1) The creation of postpersons is imaginable if they are envisaged as morally enhanced beings.

2. 2) The creation of postpersons is justified, subject to the condition that we create morally enhanced postpersons.

The reason given for the first point is that it is possible to imagine postpersons who are morally enhanced, provided that we consider moral enhancement as an augmented inclination to act in line with how we believe we ought to act. There are two reasons offered for the second point: the first indicates probability, and the second offers proof. That is, if we assume that the higher moral status of postpersons implies their enhanced morality, we can conclude, inductively, that (morally enhanced) postpersons will not be inclined to annihilate mere persons. For if mere persons have moral inhibitions against obliterating some species of a lower moral status than their own, morally enhanced postpersons will be even less likely to do the same to mere persons. In fact, they might consider it their moral duty to preserve those beings who enabled them to come into existence. Moreover, even if morally enhanced postpersons decide to annihilate mere persons, we can conclude, deductively, that such a decision is by necessity a morally superior stance to the wish of mere persons (i.e., morally unenhanced persons) to continue to exist.