jan 1, 1637 - People: Rene Descartes Rene Descartes is one of the most revolutionary philosophical and mathematical minds to come from the Enlightenment movement. He introduced many ideas into mathematics that we still use to this day, such as the rule of signs. I chose Descartes over another philosopher/mathematician, Gottfried Wilhelm Leibniz, because Descartes is an example of someone in the same field of work who accomplished so much more than Leibniz did in the long run. (Source: Wikipedia) (Timeline)