This thesis is basically an attempt to discuss the intrinsic intersubjective nature of the so-called ideal sciences, i.e. geometry or arithmetic. Based upon a thorough analysis of Husserls The Origin of Geometry and Derridas Edmund Husserl's Origin of Geometry: an Introduction this thesis takes geometry as an example of an ideal science. The main question of the thesis is how an ideal science or object is constituted. The thesis consist of two main chapters - ?Geometry and Historicity? and ?Language?- and a concluding discussion.