This work is conceived essentially as a historical study of the origin and development of one of the key concepts in Husserl's philosophy. It is not primarily meant to be an introduction to Husserl's thought, but can serve this purpose because of the nature of this concept. The doctrine of constitution deals with a philosophical problem that is fairly easy to grasp, and yet is central enough in the philosophy of Husserl to provide a con- venient viewpoint from which other concepts and problems can be considered and understood. Husserl's thoughts on the phe- nomenological reduction, on...