THE EDGE OF HISTORY 165Besso [E3], shows that access to the literature was difficult for the man from the
patent office. In his reply to Einstein's letter, Stark mentioned work by Planck,
von Laue, and himself and added, 'Apart from these papers and those mentioned
by you, I do not know of any others either' [SI]. Thus neither Einstein nor Stark
was aware of Poincare's long paper bearing on relativity, completed in July 1905
and published in the 1906 volume of Rendiconti del Circolo matematico di
Palermo [PI]. Minkowski referred to this article on November 5, 1907, in his
lecturef before the Goettinger Mathematische Verein [Ml]. It is therefore certain
that this publication was in circulation in December 1907, the time at which Ein-
stein completed his review, and a fortiori in March 1908, when he added some
corrections and comments to the review [E4]. Nevertheless, especially in view of
the exchange between Einstein and Stark, I see no grounds for thinking that in
1907 Einstein knew of Poincare's paper and chose to ignore it.
I believe, however, that Einstein's complaint about his difficulties in getting
hold of books and journals, while no doubt genuine, is only a secondary factor in
the understanding of his handling of existing literature. The truth of the matter
is that he did not much care. Read for example what he wrote in the introduction
to a paper published in 1906: 'It seems to me to be in the nature of the subject,
that what is to follow might already have been partially clarified by other authors.
However, in view of the fact that the questions under consideration are treated
here from a new point of view, I believed I could dispense with a literature search
which would be very troublesome for me, especially since it is to be hoped that
other authors will fill this gap, as was commendably done by Herr Planck and
Herr Kaufmann on the occasion of my first paper on the principle of relativity'
[E5].* This statement is not arrogant if, and only if, arrogance is a mark of inse-
curity. To me these lines express ebullience, total self-assurance, and a notable
lack of taste.**
The period during which Einstein was unaware of Poincare's technical writing
on relativity now stretches into 1908. I noted in Section 6b that by 1905 Einstein
had already read Poincare's La Science et I'Hypothese, in which it is conjectured
that the undetectability of the earth's motion relative to the aether should hold to
fSee Section 7c.
*"Es scheint mir in der Natur der Sache zu liegen, dasz das Nachfolgende zum Teil bereits von
anderen Autoren klargestellt sein diirfte. Mit Riicksicht darauf jedoch, dasz hier die betreffenden
Fragen von einem neuen Gesichtspunkt aus behandelt sind, glaubte ich, von einer fur mich sehr
umstandlichen Durchmusterung der Literatur absehen zu diirfen, zumal zu hoffen 1st, dasz diese
Liicke von anderen Autoren noch ausgefiillt werden wird, wie dies in dankenswerter Weise bei mei-
ner ersten Arbeit iiber das Relativitatsprinzip durch Hrn. Planck und Hrn. Kaufmann bereits ge-
schehen ist."
** Einstein was evidently able to get to the literature if he set his mind to it. A number of journals
are quoted in his 1907 paper [El], including even the American Journal of Science of 1887 in which
the Michelson-Morley experiment was reported. I would not be surprised if Einstein had copied
that reference from one of Lorentz's papers. Also, in 1906 Einstein mentioned [E6] a paper by
Poincare [P2] which came to his attention because it appeared in a Festschrift for Lorentz.