In the Spring of 1907, German philosopher Edmund Husserl gave five lectures in Göttingen in which he introduced the main ideas of his later phenomenology. This book contains the five lectures, along with a summary of the lectures Husserl wrote for his own use.

The key elements of phenomenology are all here, from the époche and epistemological reduction to the relationship of imminence, transcendence, and cognition. Husserl developed these tools to find a way to get at pure phenomena in their self-givenness, apart from the layers of theory and reasoning which accrue over time.

This is one of those books that most people won’t be interested in, I know. That said, if you are involved in the resurgence of phenomenology either as an area of philosophy, or as a research method, The Idea of Phenomenology is an concise yet dense exposition from the father of phenomenology himself.

Husserl, Edmund. The Idea of Phenomenology. Translated by William P. Alston and George Nakhnikian. Martinus Nijhoff, 1973.