Many and One: Division, Unity, and the Boundaries of a Corpus in Plato and Aristotle is the journal article cut from the reading copy of the same name (#1575), deposited as submitted to Ancient Philosophy on 2026-09-01 (v2.13-AP) and declined by its editor the next day without full reading. It begins from a tension in Aristotle's own words: at Sophistical Refutations 34 he says that of his inquiry nothing at all existed beforehand (οὐδὲν παντελῶς ὑπῆρχεν, 183b35), while at Prior Analytics I.31 he calls division, the method practised throughout the Platonic dialogues, a part of that inquiry. The paper argues that Metaphysics Λ 9 supplies the answer I.31 withholds — division terminates where the terms it separates are not other — and follows that answer through the De anima (one in actuality, many in potentiality), the Sophist (many true accounts of one kind), recollection in the Phaedrus and De memoria, and two passages that divide a person (Republic 395b, Symposium 223d). The section heads are the questions the reader must stay with: what would it mean for division to terminate; how can one thing be actually one and potentially many; how can many accounts belong to one thing; what is it to gather a plurality into one; which word moves. §6 first reads the corpus as anyone's work and distinguishes functional from biographical unity; §7 reads the many voices as many objects; §8 reports two measured tests — the object-conditioning null and the six-function transmission probe — and argues their nativity to the question, since the received early–middle–late order of the Platonic corpus is itself substantially a stylometric construction and the ancient collection of the corpus was made on internal criteria; §9 asks which word moves; §10, the epilogue, returns to the flood and what survives it. The historical hypothesis is withheld until §9.4 and stated nowhere before it; the paper's result is that two is not fully established — the standard attribution is underdetermined by the passages read as though it were, the texts themselves offer one maker as a reading, and that reading makes better sense of several passages. Every rival reading is stated at its strongest before it is answered. The technical report cited at n. 18 is #1572; the reception measurement made on the paper's opening sentence after the decline is #1574, The Particle.