Returning to Montaigne's famous claim of 'consubstantiality' with his book, this article examines the place of authorship in the Essais. It proposes that Montaigne constructs an authorial 'doubleness', a technique by which static text yields multiple readings depending on how and with whom we associate the role of 'authorship'. At the close of the 'Apologie de Raimond Sebond', Montaigne silently transcribes a lengthy passage from Plutarch's 'Que signifioit ce mot E'i' on the inherent flux of all things, including thought and judgement. This is taken as a case study to show how Montaigne destabilises the notion of the 'autheur', moving 'authorship' to the in-between space of the page and allowing multiple authors to come in and out of focus as we change our perspective. This textual plurality provides Montaigne with a new way of writing doubtfully, of constructing a 'forme d'escrire douteuse et irresolue'.