NATURE 



THURSDAY, NOVEMBER 28, 1912. 



SCIENTIFIC WORTHIES. 



XXXIX. — Prof. Jules Henri Poincar^, 

 For.Mem.R.S. 



IT has only happened on one or two occasions 

 that the subject of an article in our series of 

 Scientific Worthies has had to be referred to in 

 the past tense; and we deplore that such should 

 be the case now. Many men of science continued 

 to make important additions to the monument of 

 natural knowledge long- after contemporary con- 

 tributors to this series had paid tribute to their 

 acliievements, and fortunately some are still with 

 us. A testimony to good and faithful work has 

 its interest vastly increased when it can be accom- 

 panied by the thought that past performances may 

 be equalled, or even excelled, by future accomplish- 

 ments. This satisfaction is denied us when Finis 

 has to be written against a man's work; and 

 though the coral-rock represented by it may be 

 strong and beautiful, it lacks those qualities of 

 activity and growth which were once manifest on 

 its summit and are essential attributes of the 

 scientific spirit. 



A great man of science builds not so much for 

 his own generation as for the generations which 

 follow him. As M. Berthelot once said : — " If 

 each of us adds something to the commcn domain 

 in the field of science, of art, of moraE'v, it is 

 because a long series of generations havo lived, 

 worked, thought, and suffered before us.'" For 

 workers of to-day and to-morrow M. P.>:n- 

 care not only opened new fields, but pointed 

 the way to discovery by those who follow 

 him. Mathematics, physics, astronomy, philo- 

 sophy, and other domains of intellectual ac- 

 tivit\ have all been extended and illuminated by 

 his genius. The search for truth was for him a 

 passion, and all his work was animated by it. 

 His " Science and Hypothesis " represents an 

 examination into the solidity of the foundations 

 upon which scientific reasoning is based. To the 

 superficial reader the work may appear icono- 

 clastic, but many of the images it destroys should 

 never be set up in the temple of scientific belief ; 

 and if they cannot stand before the strong rays 

 of relentless logic, science is better without them. 

 For in nature 



''Beauty is truth, truth beauty; that is all 

 Ye know on earth, and all ye need to know." 



That such a brilliant and original thinker as 

 M. Poincare should have died, on July 17 last, at 

 .he relatively early age of fifty-eight is a cause of 



NO. 2248, VOL. go] 



world-wide regret. It would take several articles 

 to do justice to his work and scholarship, but we 

 must here limit ourselves to appreciative mention 

 of a few prominent points of a remarkable career. 



M. Poincare was born at Nancy on April 29, 

 1854, and commenced his studies at the Lycee 

 there. He afterwards oassed successively through 

 I'Ecole Polytechnique and I'Ecole nationale 

 superieure des Mines, receiving his doctor's degree 

 in mathematical sciences from the University of 

 Paris in 1879. He then began his career as in- 

 structor in mathematical analysis at the University 

 of Caen, from which position he was called in 1881 

 to occupy the chair of physical and experimental 

 mechanics at the Sorbonne (University of Paris). 

 Later he occupied the chair of mathematical 

 physics, and, after the death of M. Tisserand, he 

 passed to that of mathematical astronomy and 

 celestial mechanics. M. Poincare was elected a 

 member of the Paris Academy of Sciences in 1887, 

 and a member of the French Academy in 1908. 

 He w^as president of the Academy of Sciences in 

 1906, and of the Bureau des Longitudes in 1899 

 and 1909. He was also an honorary member of 

 most of the leading scientific societies of the 

 world, and received honorary degrees from the 

 Universities of Oxford, Cambridge, Glasgow, 

 Christiania, Stockholm, and Brusrols. In 1901 

 the first award of the Sylvester medal of the Royal 

 Society was made to him in recognition of his many 

 and important contributions to mathematical 

 science. 



The first volume of a series entitled " Savants 

 du Jour," published in 1909 by Messrs. Gauthier- 

 Villars, of Paris, is devoted to M. Poincare, and it 

 contains a list of more than four hundred of his 

 publications relating to mathematical analysis, 

 analytical and celestial mechanics, mathe- 

 matical physics, and philosophy of science. But 

 the value of Poincare's work is not to 

 be estimated merely by its bulk, although 

 that is unusually large ; he never wasted 

 words or wrote on trifles, and his shortest 

 notes, like those of Hermite, are always worth 

 attention. Again, the range of his topics 

 was very wide ; arithmetic, probability, function- 

 theory, dynamics, mathematical physics are all in- 

 debted to him for results of interest and often 

 of the greatest im.portance. Finally, he had, in 

 the highest degree, the gift of literary style ; few 

 of his scientific compatriots can rival him in direct- 

 ness, simplicity, and grace. There is a story that 

 Clifford, during- a walk with a friend, made him 

 understand the gist of Abel's theorem; it is easy 

 to imagine Poincare, in similar circumstances, suc- 



O 



