20th-century Dutch philosophers

Gerardus Johannes Petrus Josephus Bolland (9 June 1854, Groningen – 11 February 1922, Leiden), also known as G.J.P.J. Bolland, was a Dutch autodidact, linguist, philosopher, biblical scholar, and lecturer. An excellent orator, he gave extremely well attended public lectures in Amsterdam, Rotterdam, The Hague, Utrecht, Delft, Groningen, Nijmegen and Belgium.
He became an expert in German idealism, being especially interested in the works of Eduard von Hartmann and Georg Wilhelm Friedrich Hegel. He began researching the formation of Christianity in 1891, and was extremely literate in religious history. He was associated with the Dutch radical school.
He effected a revival in Hegelianism in the Netherlands around 1900 by arranging a new edition of Hegel’s works, and stimulating a renewal of interest in philosophy in the Netherlands. He had a quirky style in his use of the Dutch language causing linguist J.A. Dèr Mouw, among others, to criticise him sharply.

Luitzen Egbertus Jan "Bertus" Brouwer (27 February 1881 – 2 December 1966) was a Dutch mathematician and philosopher who worked in topology, set theory, measure theory and complex analysis. He is seen as one of the founders of modern topology, in particular through his establishing the fixed-point theorem and the topological invariance of dimension.Brouwer also became a major figure in the philosophy of intuitionism, a constructivist school of mathematics which argues that math is a cognitive construct rather than a type of objective truth. This position led to the Brouwer–Hilbert controversy, in which Brouwer sparred with his formalist colleague David Hilbert. Brouwer's ideas were subsequently taken up by his student Arend Heyting and Hilbert's former student Hermann Weyl. In addition to his mathematical work, Brouwer also published the short philosophical tract Life, Art, and Mysticism (1905).