Henri Poincare 1854 – 1912

Jules Henri Poincare was a French mathematician, theoretical physicist, and philosopher of science, often described as the last universalist of mathematics. He made foundational contributions to topology, dynamical systems, and special relativity, and his philosophical essays on the methodology of mathematics and the natural sciences, collected in Science and Hypothesis, The Value of Science, and Science and Method, helped to inaugurate modern philosophy of science. He defended a conventionalist account of geometry and a creative role for the working mathematician's intuition.

Henri Poincare was born in 1854 at Nancy into a distinguished French family — his cousin Raymond Poincare would become President of the Republic. He took the entrance examination at the Ecole polytechnique at the top of the list, continued at the Ecole des Mines, and from 1881 taught at the University of Paris, holding successive chairs in mathematical physics, mechanics, and mathematical astronomy until his death.

His mathematical, physical, and philosophical output filled more than thirty volumes. The mathematical work included the founding of algebraic topology and the theory of automorphic functions, decisive contributions to the three-body problem and celestial mechanics, and the famous 1904 conjecture solved a century later. The popular and philosophical writings include Science and Hypothesis (1902), The Value of Science (1905), Science and Method (1908), and the posthumous Last Thoughts.

Poincare argued that geometric axioms are conventions chosen for their convenience rather than empirical discoveries or synthetic a priori truths, defended a structural realism about scientific theories, and gave the philosophy of science one of its most lucid voices on the relations of intuition, logic, and creative invention in mathematics. His conventionalism shaped the early Vienna Circle and continues to be discussed. He died in Paris in July 1912.