Pascal had intended to write a major treatise concerning the nature of the vacuum; like so many of his works, it was never completed. All that we possess of this project is a remarkable fragment, 'Preface pour Ie Traite du Vide,' written in 1647. The copy on which the presentday text is based was made by Father Beurrier, who transcribed it from what he called a highly imperfect copy, filled with lacunae. Bossuet was the first to publish the 'Preface,' at the beginning of his edition of the Pensees. Bossuet gave the 'Preface' the title 'De l'autorite en matiere de philosophie' - 'Concerning Authority in the Matter of Philosophy.'