THE NEW DYNAMICS 283the new [i.e., the Einstein-Grossmann] theory' [E32]. In his later years, however,
Mach turned his back on relativity. In July 1913 he wrote, 'I must ... as
assuredly disclaim to be a forerunner of the relativists as I withhold from the
atomistic belief of the present day,' and added that to him relativity seemed 'to be
growing more and more dogmatical' [M9]. These phrases appear in a book that
was not published until 1921. Even so, Einstein's esteem for Mach never faltered.
'There can hardly be any doubt that this [reaction by M.] was a consequence of
an absorption capacity diminished by age, since the whole direction of thinking of
this theory is in concordance with that of Mach, so that it is justified to consider
Mach as the precursor of the general theory of relativity,' he wrote in 1930 [E33].
In the last interview given by Einstein, two weeks before his death, he reminisced
with evident pleasure about the one visit he had paid to Mach and he spoke of
four people he admired: Newton, Lorentz, Planck, and Mach [G2]. They, and
Maxwell, and no others, are the only ones Einstein ever accepted as his true
precursors.In a discussion of Mach's influence on Einstein, it is necessary to make a clear
distinction between three themes.
First, Mach's emphasis on the relativity of all motion. As we have just seen, in
this regard Einstein's respect was and remained unqualified.
Second, Mach's philosophy or, perhaps better, his scientific methodology.
'Mach fought and broke the dogmatism of nineteenth century physics' is one of
the rare approving statements Einstein ever made about Mach's philosophical
positions [E34]. In 1922 he expressed himself as follows before a gathering of
philosophers. 'Mach's system [consists of] the study of relations which exist
between experimental data; according to Mach, science is the totality of these
relations. That is a bad point of view; in effect, what Mach made was a catalog
and not a system. Mach was as good at mechanics as he was wretched at philos-
ophy.* This short-sighted view of science led him to reject the existence of atoms.
It is possible that Mach's opinion would be different if he were alive today' [E35].
His negative opinion of Mach's philosophy changed as little during his later years
as did his admiration for Mach's mechanics. Just before his death,
Einstein said he had always believed that the invention of scientific concepts
and the building of theories upon them was one of the creative properties of the
human mind. His own view was thus opposed to Mach, because Mach assumed
that the laws of science were only an economical way of describing a large col-
lection of facts. [C2]***'Autant Mach fut un bon mechanician, autant il fut un deplorable philosophe.'
**In his autobiographical sketch, Einstein mentioned that the critical reasoning required for his
discovery of special relativity was decisively furthered by his reading of Mach's philosophical writ-
ings [E27]. I would venture to guess that at this point Einstein had once again Mach's mechanics in
mind.