  The historical movement of phenomenology is the philosophical tradition launched in the first half of the 20th century by Edmund Husserl, Martin Heidegger, Maurice Merleau-Ponty, Jean-Paul Sartre, et al. In that movement, the discipline of phenomenology was prized as the proper foundation of all  philosophy—as opposed, say, to ethics or metaphysics or epistemology. The methods and characterization of the discipline were widely debated by Husserl and his successors, and these debates continue to the present day. (The definition of phenomenology offered above will thus be debatable, for example, by Heideggerians, but it remains the starting point in characterizing the discipline.)