Edmund Husserl (April 8, 1859 - April 26, 1938) was the originator of the phenomenological movement and a pupil of Franz Brentano. He would influence Martin Heidegger, Jean-Paul Sartre, and Maurice Merleau-Ponty, among others. (Hermann Weyl's interest in intuitionistic logic and impredicativity, for example, seems to have been as a result of contact with Husserl.)
Husserl is best known for his extensive use of the notion that the main characteristic of consciousness is that it is always intentional, i.e. directed at some kind of content ("Inhalt"): consciousness is always "consciousness of something." He borrowed the concept of the intentional from Brentano, as can be seen from the latter's Psychologie vom empirischen Standpunkt (Psychology from an Empirical Standpoint). Further, he asserted that studying the flow of consciousness as directed (the act of noesis) at the perceived phenomena (the noemata) yields knowledge of essential structures in reality.
In the last period of his life, Husserl shifted to a more explicitly idealist position, which is best expressed in his Cartesian Meditations (1931). His main work, however, remains Logische Untersuchungen (Logical Investigations; first edition, 1900-1901).
Husserl, who was born into a Jewish familly in Prostejov (Prossnitz) in Moravia (now in the Czech Republic), was eventually denied the use of the university library at Freiburg former, because of the racial cleansing laws issued by the Nazi party, and carried out at the university by Martin Heidegger, Husserl's most famous pupil. Moreover, Heidegger removed the dedication to Husserl from his most widely known work Being and Time when it was reissued in 1941.