: His ultimate conclusion—"I think, therefore I am"—established the thinking self as the only undeniable truth.
Descartes revolutionized science by bridging the gap between two previously separate fields: and Geometry . Cartesian Coordinate System : By using a grid (the Cartesius
axes), he allowed geometric shapes to be expressed as algebraic equations. : His ultimate conclusion—"I think
: He famously discarded any belief that could be doubted, including the reliability of the senses. including the reliability of the senses.