Henri Poincaré (full name Jules Henri Poincaré)
French mathematician and philosopher of science. Although he granted the necessity of testing scientific propositions against observed facts about the natural world inLa Science et l'hypothèse (Science and Hypothesis) (1902) Poincaré emphasized that scientific theories are conventional claims best supported by appeal to their simplicity and utility rather than to their truth. This philosophy of science provided a significant impetus for logical positivism, but Poincaré himself criticized the logicization of arithmetic inDernières Pensées (Mathematics and Science: Last Essays) (1912).
Henri Poincaré is often described as the last universalist who understood and contributed in virtually all parts of mathematics. He was a populariser of mathematics and physics and wrote several books for the lay public.
He had an amazing memory and could state the page and line of any item in a text he had read. He was also able to remember verbatim by ear. He retained these abilities throughout his life.
His normal work habit was to solve a problem completely in his head, then commit the completed problem to paper.
He was however physically clumsy and artistically inept. He was always in a rush and disliked going back for changes or corrections.
Poincaré kept very precise working hours. He undertook mathematical research for four hours a day, between 10 am and noon then again from 5 pm to 7 pm. He would read articles in journals later in the evening.
Henri was ambidextrous and nearsighted. His ability to visualise what he heard proved particularly useful when he attended lectures since his eyesight was so poor that he could not see properly what his lecturers were writing on the blackboard.Taken from: