Meditationes de Prima Philosophia is widely recognized as Descartes’ most important work, and a watershed book in the history of Western philosophy. Before Descartes’ Meditations, philosophers asked, What must the world be like so that we find it intelligible? Afterward, they tended to ask, What must the mind be like in order for the world to be intelligible to it? The nature of awareness itself, independent of any particular object of awareness, became an issue for philosophy. Descartes’ own aims in the Meditations were to demonstrate the existence and transcendence of God, as well as the distinctness of body and soul, and to show that the best way to investigate nature is via a geometrical method that subordinates and defers the records of sense, in order to best exhibit their meaning. The emergence of human consciousness as a topic stems from the second aim and its introduction via doubt and reflection in the first two Meditations.

The argument of the Meditations is given very briefly in part 4 of the Discourse on Method. Descartes circulated his new, expanded presentation first to two Dutch colleagues, who showed it to Johannes Caterus; the first set of “Objections,” to which Descartes wrote “Replies,” are thus from Caterus. Descartes sent the text and the first set of the Objections and Replies to his friend and agent in Paris, Marin Mersenne, who circulated them to various philosophers and Jesuits, including Morin, Hobbes, Arnauld, Gassendi, and Bourdin. The first edition of the Meditations was published in Paris in 1641, with six sets of Objections and Replies appended; a seventh set was added for the second edition published in Amsterdam in 1642.