This book presents a systematic discussion of the development of Husserl's concept of the a priori from his early and through his later writings. The chapters contained herein analyze the different phases and aspects of Husserl's phenomenology of the a priori in light of his twofold notion of reason, construed as both ontological and transcendental.

Starting from the assessment of the introduction of the notion of a priori knowledge in the context of the Logical Investigations, this text uniquely explores its development during the G