Einstein, in conversation with Moszkowski, expressed doubt as to the reality of Leonardo’s previsions of modern science. But it scarcely appeared that he had investigated the matter, while the definite testimony of the experts in many fields who have done so cannot be put aside. Footnote 46: For the Italian reader of Leonardo the fat little volume of _Frammenti_, edited by Dr. Solmi and published by Barbèra, is a precious and inexhaustible pocket companion. For the English reader Mr. MacCurdy’s larger but much less extensive volume of extracts from the _Note-Books_, or the still further abridged _Thoughts_, must suffice. Herbert Horne’s annotated version of Vasari’s _Life_ is excellent for Leonardo’s personality and career. Footnote 47: Morley Roberts, who might be regarded as a pupil in the school of Leonardo and trained like him in the field of art, has in various places of his suggestive book, _Warfare in the Human Body_, sprinkled irony over the examples he has come across of ignorant specialists claiming to be men of “science.” Footnote 48: Needless to say, I do not mention this to belittle Galton. A careful attention to words, which in its extreme form becomes pedantry, is by no means necessarily associated with a careful attention to things. Until recent times English writers, even the greatest, were always negligent in spelling; it would be foolish to suppose they were therefore negligent in thinking. Footnote 49: Darwin even overestimated the æsthetic element in his theory of sexual selection, and (I have had occasion elsewhere to point out) unnecessarily prejudiced that theory by sometimes unwarily assuming a conscious æsthetic element. Footnote 50: It is probable that the reason why it is often difficult to trace the imaginative artist in great men of supposedly abstract science is the paucity of intimate information about them. Even their scientific friends have rarely had the patience, or even perhaps the intelligence, to observe them reverently and to record their observations. We know almost nothing that is intimately personal about Newton. As regards Einstein, we are fortunate in possessing the book of Moszkowski, _Einstein_ (translated into English under the title of _Einstein the Searcher_), which contains many instructive conversations and observations by a highly intelligent and appreciative admirer, who has set them down in a Boswellian spirit that faintly recalls Eckermann’s book on Goethe (which, indeed, Moszkowski had in mind), though falling far short of that supreme achievement. The statements in the text are mainly gleaned from Moszkowski. Footnote 51: Spengler holds (_Der Untergang des Abendlandes_, vol. X, p. 329) that the development of music throughout its various stages in our European culture really has been closely related with the stages of the development of mathematics. Footnote 52: