Luitzen Egbertus Jan "Bertus" Brouwer was a Dutch mathematician and philosopher who worked in topology, set theory, measure theory and complex analysis. Regarded as one of the greatest mathematicians
Brouwer (right) at the International Mathematical Congress, Zurich 1932
Gerrit Mannoury was a Dutch philosopher and mathematician, professor at the University of Amsterdam and communist, known as the central figure in the signific circle, a Dutch counterpart of the Vienna