Dirk Hendrik Theodoor Vollenhoven (1 November 1892, in Amsterdam – 6 June 1978, in Amsterdam) was a Dutch philosopher. Life history and early work Vollenhoven was born in Amsterdam, son of Dirk Hendrik Vollenhoven and Catharina Pruijs. His father was a custom-house officer of telegraphy in Amsterdam. In 1911, Vollenhoven registered in two faculties at the Vrije Universiteit in Amsterdam, the Faculty of Theology and the Faculty of Arts and Philosophy, and obtained his PhD in philosophy (cum laude) in 1918. He was a pastor of the Reformed Churches, first in Oostkapelle, 1918-1921, then in The Hague, 1921-1926. He was appointed professor of philosophy at the Vrije Universiteit in 1926, and retired in 1963. On 10 October 1918 he married Hermina Maria Dooyeweerd (1892-1973). They had five children, two girls and three boys. Vollenhoven was a person who combined direct clarity with deep insight. He had an analytical mind that mastered many distinctions. He was pious, modest, obliging, and dedicated in his many tasks. In the faculty of Arts and Philosophy he gave, from 1926 till 1954, all the courses in philosophy: history of philosophy, general systematic philosophy, logic, and theoretical psychology (the latter was considered to be a philosophical discipline at the time), and also the mandatory introduction to philosophy for first-year students of all the faculties. While preparing his dissertation on the influence of philosophy on mathematics and the natural sciences, Vollenhoven preached practically every Sunday, thereby becoming a well-known figure in the Reformed Churches. A year before gaining his PhD both his father and his supervisor and tutor, J. Woltjer, died. G.H.J.W.J. Geesink stepped in to supervise the completion of the thesis (now with restricted topic), entitled: “The philosophy of mathematics from a theistic standpoint.” The Amsterdam mathematician, Gerrit Mannoury, whom Vollenhoven had critically described as being “the most consequential formalist and communistic pragmatist,” responded sympathetically to the dissertation by saying that Vollenhoven had taken a path “that had not been blazed by anyone before,” and that he did this “neither as theologian nor as mathematician, but as one who cherished his faith, yet without despising thought.” In the parsonage in Oostkapelle, and later in The Hague, Vollenhoven performed his duties conscientiously, but he also continued his study of philosophy. In 1920 he received a scholarship and leave of absence to study psychology under Felix Krueger for five months in Leipzig. In the early 1920s neo-Kantianism was