Descartes 

In Mathematics, Descartes chief contribution was in analytical geometry. Descartes saw that a point in a plane could be completely determined if its distances (conventionally 'x' and 'y') were given from two fixed lines drawn at right angles in the plane, with the nowfamiliar convention of interpreting positive and negative values. Conventionally, such coordinates are referred to as "The Rectangular Cartesian Coordinate System". (see coordinate systems). Descartes asserted that, similarly, a point in 3dimensional space could be determined by three coordinates.
“It is not enough to have a good mind. The main thing is to use it well”. René Descartes 1637