Edmund Gustav Albrecht Husserl (April 8, 1859, Prostějov, Moravia, Austrian Empire – April 26, 1938, Freiburg, Germany) was a philosopher who is deemed the founder of phenomenology. He broke with the positivist orientation of the science and philosophy of his day, believing that experience is the source of all knowledge, while at the same time he elaborated critiques of psychologism and historicism.

Born into a Moravian Jewish family, he was baptized as a Lutheran in 1887. Husserl studied mathematics under Karl Weierstrass, completing a Ph.D. under Leo Königsberger, and studied philosophy under Franz Brentano and Carl Stumpf. Husserl taught philosophy, as a Privatdozent at Halle from 1887, then as professor, first at Göttingen from 1901, then at Freiburg im Breisgau from 1916 until his 1928 retirement. Husserl's teaching and writing influenced, among others, Martin Heidegger, Jean-Paul Sartre, Emmanuel Levinas, Maurice Merleau-Ponty, Kurt Gödel, Alfred Schütz, Paul Ricœur, Jacques Derrida, Dietrich von Hildebrand and Francisco Varela.

Husserl was born in 1859 into a Jewish family in Prostějov, a town that was then in the Austrian Empire, after 1918 a part of Czechoslovakia, and since 1993 a part of the Czech Republic. He initially studied mathematics at the universities of Leipzig (1876) and Berlin (1878), under Karl Weierstrass and Leopold Kronecker. In 1881 he went to Vienna to study under the supervision of Leo Königsberger (a former student of Weierstrass), obtaining the Ph.D. in 1883 with the work Beiträge zur Variationsrechnung ("Contributions to the Calculus of Variations"). In 1884, he began to attend Franz Brentano's lectures on psychology and philosophy at the University of Vienna. Husserl was so impressed by Brentano that he decided to dedicate his life to philosophy. In 1886 Husserl went to the University of Halle to obtain his Habilitation with Carl Stumpf, a former student of Brentano. Under his supervision he wrote Über den Begriff der Zahl (On the concept of Number; 1887) which would serve later as the base for his first major work, Philosophie der Arithmetik (1891).

In these first works he tries to combine mathematics, psychology and philosophy with a main goal to provide a sound foundation for mathematics. He analyzes the psychological process needed to obtain the concept of number and then tries to build up a systematical theory on this analysis. To achieve this he uses several methods and concepts taken from his teachers. From Weierstrass he derives the idea that we generate the concept of number by counting a certain collection of objects. From Brentano and Stumpf he takes over the distinction between proper and improper presenting. In an example Husserl explains this in the following way: if you are standing in front of a house, you have a proper, direct presentation of that house, but if you are looking for it and ask for directions, then these directions (e.g. the house on the corner of this and that street) are an indirect, improper presentation. In other words, you can have a proper presentation of an object if it is actually present, and an improper (or symbolic as he also calls it) if you only can indicate that object through signs, symbols, etc. Husserl's 1901 Logical Investigations is considered the starting point for the formal theory of wholes and their parts known as mereology.

Another important element that Husserl took over from Brentano is intentionality, the notion that the main characteristic of consciousnessis that it is always intentional. While often simplistically summarised as "aboutness" or the relationship between mental acts and the external world, Brentano defined it as the main characteristic of mental phenomena, by which they could be distinguished from physical phenomena. Every mental phenomenon, every psychological act, has a content, is directed at an object (the intentional object). Every belief, desire, etc. has an object that it is about: the believed, the wanted. Brentano used the expression "intentional inexistence" to indicate the status of the objects of thought in the mind. The property of being intentional, of having an intentional object, was the key feature to distinguish mental phenomena and physical phenomena, because physical phenomena lack intentionality altogether.

Some years after the publication of his main work, the Logische Untersuchungen (Logical Investigations; first edition, 1900-1901), Husserl made some key conceptual elaborations which led him to assert that in order to study the structure of consciousness, one would have to distinguish between the act of consciousness and the phenomena at which it is directed (the objects as intended). Knowledge of essences would only be possible by "bracketing" all assumptions about the existence of an external world. This procedure he called epoché. These new concepts prompted the publication of the Ideen (Ideas) in 1913, in which they were at first incorporated, and a plan for a second edition of the Logische Untersuchungen.

From the Ideen onward, Husserl concentrated on the ideal, essential structures of consciousness. The metaphysical problem of establishing the material reality of what we perceive was of little interest to Husserl in spite of his being a transcendental idealist. Husserl proposed that the world of objects and ways in which we direct ourselves toward and perceive those objects is normally conceived of in what he called the "natural standpoint", which is characterized by a belief that objects materially exist and exhibit properties that we see as emanating from them. Husserl proposed a radical new phenomenological way of looking at objects by examining how we, in our many ways of being intentionally directed toward them, actually "constitute" them (to be distinguished from materially creating objects or objects merely being figments of the imagination); in the Phenomenological standpoint, the object ceases to be something simply "external" and ceases to be seen as providing indicators about what it is, and becomes a grouping of perceptual and functional aspects that imply one another under the idea of a particular object or "type". The notion of objects as real is not expelled by phenomenology, but "bracketed" as a way in which we regard objects instead of a feature that inheres in an object's essence founded in the relation between the object and the perceiver. In order to better understand the world of appearances and objects, phenomenology attempts to identify the invariant features of how objects are perceived and pushes attributions of reality into their role as an attribution about the things we perceive (or an assumption underlying how we perceive objects).

In a later period, Husserl began to wrestle with the complicated issues of intersubjectivity, specifically, how communication about an object can be assumed to refer to the same ideal entity. Husserl tries new methods of bringing his readers to understand the importance of phenomenology to scientific inquiry (and specifically to psychology) and what it means to "bracket" the natural attitude. The Crisis of the European Sciences is Husserl's unfinished work that deals most directly with these issues. In it, Husserl for the first time attempts a historical overview of the development of Western philosophy and science, emphasizing the challenges presented by their increasingly empirical and naturalistic orientation. Husserl declares that mental and spiritual reality possess their own reality independent of any physical basis, and that a science of the mind ('Geisteswissenschaft') must be established on as scientific a foundation as the natural sciences have managed.

Professor Husserl was denied the use of the library at Freiburg as a result of the anti-Jewish legislation the Nazis passed in April 1933. It is rumoured that his former pupil and Nazi Party member, Martin Heidegger, informed Husserl that he was discharged, but Heidegger later denied this, labelling it as slander. Heidegger (whose philosophy Husserl considered to be the result of a faulty departure from, and grave misunderstanding of, Husserl's own teachings and methods) removed the dedication to Husserl from his most widely known work, Being and Time, when it was reissued in 1941. This was not due to diminishing relations between the two philosophers, however, but rather as a result of a suggested censorship by Heidegger's publisher who feared that the book may be banned by the Nazi regime. The dedication can still be found in a footnote on page 38, thanking Husserl for his guidance and generosity. 

After his death, Husserl's manuscripts, amounting to approximately 40,000 pages of "Gabelsberger" stenography and his complete research library, were smuggled to Belgium by Herman Van Breda in 1939 and deposited at Leuven to form the Husserl Archives of the Higher Institute of Philosophy. Much of the material in his research manuscripts has been published in the Husserliana critical edition series.