The Phenomenology of Mind is Hegel's most widely discussed philosophical work. Hegel described the work as an "exposition of the coming to be of knowledge". This is explicated through a necessary self-origination and dissolution of "the various shapes of spirit as stations on the way through which spirit becomes pure knowledge". Focusing on topics in metaphysics, epistemology, physics, ethics, history, religion, perception, consciousness, and political philosophy, it is where Hegel develops his concepts of dialectic (including the master–slave dialectic), absolute idealism, ethical life, and Aufhebung. It had a profound effect in Western philosophy.