Husserl's Ideas for a Pure Phenomenology and Phenomenological Philosophy (1913) is one of the key texts of twentieth century philosophy. It is the first of Husserl's published works to present his distinctive version of transcendental philosophy and to put forward the ambitious claim that phenomenology is the fundamental science of philosophy. In Ideas, Husserl introduces for the first time the conceptual arsenal of his mature phenomenology: the principle of all principles, the phenomenological epoch