This book starts with a representation of Husserl's idea of phenomenology as a foundational theory of science. The following essays elucidate the main features of the phenomenological method as worked out by Husserl in the course of the development of his philosophy - starting from merely 'descriptive' and going on to 'transcendental' and 'constitutive' phenomenology - in order to get access to the foundations of knowledge in general and of scientific knowledge in particular. Further essays deal with the Husserlian foundations of natural science, and the relations between phenomenology and...