Henri Poincare

Henri Poincare
Jules Henri Poincaréwas a French mathematician, theoretical physicist, engineer, and a philosopher of science. He is often described as a polymath, and in mathematics as The Last Universalist by Eric Temple Bell, since he excelled in all fields of the discipline as it existed during his lifetime...
NationalityFrench
ProfessionMathematician
Date of Birth29 April 1854
CountryFrance
observation draws observers
In one word, to draw the rule from experience, one must generalize; this is a necessity that imposes itself on the most circumspect observer.
means necessary neither nor
Thus, be it understood, to demonstrate a theorem, it is neither necessary nor even advantageous to know what it means . . . .
american-journalist governed phenomenon succeeding
If that enabled us to predict the succeeding situation with the same approximation, that is all we require, and we should say that the phenomenon had been predicted, that it is governed by the laws.
avoiding consists infinite invention useful useless
Invention consists in avoiding the constructing of useless contraptions and in constructing the useful combinations which are in infinite minority. To invent is to discern, to choose.
american-journalist cannot cause determines due effect escapes notice
A very small cause which escapes our notice determines a considerable effect that we cannot fail to see, and then we say that the effect is due to chance.
american-journalist believe both convenient equally necessity
To doubt everything, or, to believe everything, are two equally convenient solutions; both dispense with the necessity of reflection.
american-journalist species
It has adopted the geometry most advantageous to the species or, in other words, the most convenient.
american-journalist relations remain replace
Thus, they are free to replace some objects by others so long as the relations remain unchanged.
american-journalist
No more than these machines need the mathematician know what he does.
wish different looks
If one looks at the different problems of the integral calculus which arise naturally when one wishes to go deep into the different parts of physics, it is impossible not to be struck by the analogies existing.
effort difficulty
But all of my efforts served only to make me better acquainted with the difficulty, which in itself was something.
inspiration hard-work departure
All that we can hope from these inspirations, which are the fruits of unconscious work, is to obtain points of departure for such calculations. As for the calculations themselves, they must be made in the second period of conscious work which follows the inspiration, and in which the results of the inspiration are verified and the consequences deduced.
children moving history
The task of the educator is to make the child's spirit pass again where its forefathers have gone, moving rapidly through certain stages but suppressing none of them. In this regard, the history of science must be our guide.
add needs mathematician
Need we add that mathematicians themselves are not infallible?