  The Meditations opens by developing skeptical questions concerning the possibility of knowledge. Through a series of several carefully thought out meditations, the reader establishes (along with the author) the groundwork for the possibility of knowledge (scientia).  Descartes is not a skeptic, as some have insisted, but uses skepticism as a vehicle to motivate his reader to “discover” by way of philosophical investigation what constitutes this ground. In the Second Replies, Descartes refers to this style of presentation as the “analytic” style. There were two styles of presentation: analytic and synthetic. It is important not to confuse these terms with those, say, used by Kant. For Descartes the analytic style of presentation (and inquiry) proceeds by beginning with what is commonly taken to be known and discovering what is necessary for such knowledge. Thus, the inquiry moves from what is commonly known to first principles. The “discovery” moves in such a way that each discovery is based on what was discovered before. By contrast, the synthetic style of presentation begins by asserting first principles and then to determining what follows.  Prompted by Mersenne, Descartes sketches out in the Second Replies a synthetic rendering of the Meditations.