What she means: How come Rene Descartes is only remembered as a philosopher, and the guy who said "I think therefore I am"? The Cartesian plane is NAMED after him and still only hard mathematicians know that he invented it. Also, the whole Newton/Leibniz argument completely ignores the fact that Descartes allowed both of them to discover calculus, because of his theories/ideas and invaluable work with exponents - he literally laid the foundations of calculus but no one mentions him when discussing who invented it. He even invented the modern notation of writing powers as superscripts as well as the convention of using x,y,z for variables and a,b,c for constants. Most importantly he INVENTED ANALYTIC GEOMETRY and pulled everyone's collective heads out of their collective asses. He was one of the greatest mathematicians. But yeah, a cool philosopher too, let's let "Cogito Ergo Sum" be his only legacy.