Rene Descartes was a central figure in the scientific revolution of the
seventeenth century. In his Discourse on Method he outlined the contrast
between mathematics and experimental sciences, and the extent to which
each one can achieve certainty. Drawing on his own work in geometry,
optics, astronomy and physiology, Descartes developed the hypothetical
method that characterizes modern science, and this soon came to replace
the traditional techniques derived from Aristotle. Many of Descartes'
most radical ideas such as the disparity between our perceptions and the
realities that cause them have been highly influential in the
development of modern philosophy.