_Renatus Des-Cartes was born on the last day of ~March~ in the year 1596. at ~Tours~, or at ~Castrum Eraldum~ a Town near ~Tours~ in ~France~; He came of an Antient and Noble Family, being by Descent ~Lord~ of ~Perron~, His Father was a Senator of his Country, and a Man of no mean estate, leaving to this his only Son by a second Wife between six and seven thousand pounds a year._ _He was Educated in his younger years according to the manner of his Country (and as he himself recommends in one of his Epistles, ~viz. Epist. 90. partis secundæ~ to One for the Instruction of his Son) in the Aristotelian principles of Philosophy, a whole course whereof he had run through at the Age of seventeen in the Schools of ~Flexia~, or ~La Flesche~ a Town in the Province of ~Anjou~, famous for the Colledge of Jesuites there establish’d by ~Henry~ the ~4th~._ _But to this he did not Continue long devoted, giving early testimonies of his dislike to the unsatisfactory Notions, and verbose emptiness of the Peripatetick Philosophy; He used therefore his utmost endeavours (as he himself testifies in his ~Dissertatio de Methodo~) to get loose from those Chains and Fetters of Mind to which the weakness of his tender years had subjected him._ _To this end he betook himself to a long course of Travel, that by the variety of Objects, which he was likely to meet with in his journeys, the memory of his past Notions might be blotted out; In his travel he applied himself much to the study of the Art Military, and Mathematicks; In the latter he has left the World large testimonies of his Excellence in his ~Book of Geometry~; and in the former we have reason to believe him most expert, for He was personally present at some Sieges and Battles both in ~France~ and ~Germany~, as particularly at the Siege of ~Rochel~, of ~Gava~ near ~Genoa~, of ~Breda~, at the Battle of ~Prague~, ~&c.~ so that we may conclude that he had a Genius fitted (according to the Motto of the noble ~Sir W. Raliegh~) ~Tam Marti, quam Mercurio~, For the Pike as well as Pen. And as the Glorious Roman Emperour became a ~Cæsar~ by his Book as well as Sword, by the Conquests of his mind as well as those of his arm; so our Famous Author was ~Ex Utroque Clarus~._