Oscar Becker (5 September 1889 – 13 November 1964) was a German philosopher, logician, mathematician, and historian of mathematics.
Becker was born in Leipzig, where he studied mathematics. His dissertation under Otto Hölder and Karl Rohn (1914) was On the Decomposition of Polygons in non-intersecting triangles on the Basis of the Axioms of Connection and Order.
He served in World War I and returned to study philosophy with Edmund Husserl, writing his Habilitationsschrift on Investigations of the Phenomenological Foundations of Geometry and their Physical Applications, (1923). Becker was Husserl's assistant, informally, and then official editor of the Yearbook for Phenomenological Research.
He published Mathematical Existence his magnum opus, in the Yearbook in 1927. A famous work that also appeared in the Yearbook that year was Martin Heidegger's Being and Time. Becker frequently attended Heidegger's seminars during those years.
Oskar Becker (18 June 1839 in Odessa - 16 July 1868 in Alexandria) was a German political fanatic, known for his attempted assassination of William I of Prussia.
In 1859 he enrolled at Leipzig University, and in 1861, at Baden-Baden, endeavored to kill king William I of Prussia by firing two shots from a pistol, at a distance of three paces. However, the monarch suffered only a slight injury of the neck. The assailant, in a letter found upon him, stated as his motive the conviction that William was unapt of the task of uniting Germany. The assailant was sentenced to twenty years' imprisonment, but was pardoned by William, and released in 1866, with the stipulation that he should leave the German Confederation forever. He lived in Chicago for some time, and subsequently went to Alexandria, Egypt, where he died.
Becker was an uncle of artist Paula Modersohn-Becker. William later became the first emperor of the German Empire.