Scientific contributions
While Müller ended his life as the experimentalist, he did not start out as one. His second doctoral subject was experimental physics (taught by Wilhelm Weber), but his dissertation of 1873 and his habilitation of 1876 (Müller, 1878a) would today be book-length versions of a Psychological Review articles, since there is no original data in either one. In the Habilitation, he defined much of the standard psychophysics that has been passed down to students (Haupt, 1995); recommended using both ascending and descending methods of limits to limit bias and the method of constant stimuli, which he extensively developed with the Müller weights, would seem to be another method designed to improve the usefulness of a threshold, but he did not provide any new experimental data. In the early papers on memory by Müller and Schumann, he seems to have originated a number of important procedural controls for the study of association. Kroh (1935, p. 155) puts Müller in the same group (first generation of psychologists) with Stumpf and Külpe, for which the transition to being an experimentalist was a significant step; a step that was not required for anyone trained as a physicist (Fechner) or physiologist (Wundt).
Müller also made major contributions to lightness perception
(white-grey-black level) through modifications of Hering's theory
in which he added the concept of "cortical or neutral grey
(Eigengrau)" (Müller 1896a; 1896b; 1897b [cited in Boring, 1967])
for which he seems to have received an honorary M.D. from Leipzig
in 1897, just after Hering moved there (1895). Further, he
elaborated the color theory of Hering in his later life (Müller
1930a, 1930b),
Müller was one of the originators of the study of memory
(learning, as it was then known), being the first to use the word
Einstellung (it appears first in the title of Schumann, 1889),
providing procedural controls and improving the methodology of
Ebbinghaus (Müller and Schumann, 1893) and starting on the study of
inhibition, sponsored Jost's law (Jost, 1894), in order to develop
a Vorstellungsmechanik, developing the ideas of proactive
(Associative) and retroactive interference from the theories of
Herbart (Müller and Pilzecker, 1900), and thought of the discipline
of memory in a far more cognitive way than Ebbinghaus (Blumenthal,
1985b). He went on to write three major volumes (they appeared as
supplementary volumes to the Zeitschrift für Psychologie from 1911-1917) and were concerned, with, among other things, an
investigation of a mnemonist, Rückle. Much of these results were
further elaborated by Grüner-Hegge (191.a).
Eminence from contemporary sources
Simonton (1985&c) has made much of the consistency of the size
of entries in major collections of biographies of important
scientists, and used this consistency to argue that "eminence" of
a sort is measured by word counts is biographies. Yet, the
consistent use of citations by contemporaries is a sort of
eminence; an eminence that we would do well to heed. I have
collected this sort of data below:
Table 1
Citation Frequency in Major Experimental Psychology Summaries
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Source Wundt Müller Stumpf
Works Page Works Page W P
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North American Sources
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Ladd & Woodworth1 26 10
(1911)
Woodworth (1938) 29 30
Stevens (1951) 5 18
Osgood (1953) 1 2 4 7
Woodworth &
Schlosberg (1954) 5 5 6 12
Woodworth &
Schlosberg (1971) 2 5 0 0
Stevens, 2. Ed.(1988) 5 (I) 5 (II)2
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European Sources
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Fröbes (191.)
Fröbes (1917, Vol. I; 1920, Vol. II)
page 76 58
bold 6 8 11 12
ff. 13 26
running pages 16 48
Fröbes (1926)
Meili, Rohracher,
2 ed. (1968)
page 2 7 5 5
ff. 1 2
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1. This is not a particularly appropriate source, since Müller had
published fewer than half of the pages of his work in memory and
very little in color theory. In addition, for psychophysics, where
Müller had done most of his work up to this time, the reader is
referred to Titchener (1905). It is included primarily as a matter
of historical continuity. See also the comment on James (1890) in
the text.
2. This particularly demonstrates the lack of knowledge of Müller's
work.
This table shows that both during his life and After his
death, Müller was influential. The series of books on experimental
psychology written or coauthored by Woodworth (Ladd & Woodworth,
1911; Woodworth, 1938; and Woodworth & Schlosberg, 1954) became an
American standard of excellence for knowledge of experimental
psychology, and were virtually memorized to pass doctoral exams.
Only in the earliest edition (1911), in which Müller has little
chance to be fully represented, is Wundt given more citations. For
the work that Müller had then done most comprehensively,
psychophysics, the reader is referred to Titchener (1905), who
gives Müller credit for the main thrust of his work.
In Woodworth's (1938) book that is the sole product of his
exertions, there is an extensive chapter on cognition--Müller is in
every part of it, and Müller has more citations (30) than Wundt
(29). In the second edition (Woodworth & Schlosberg, 1954), the
number of works cited for Wundt is 5, and each has only 1 page
citation for a total of 5; Müller has the same number of research
works cited 5 (6 if the work with Lillien Jane Martin is included)
but a clearly larger number of page citations (11; 12 with Martin)
to Wundt's 5. For Osgood's (1953) nearly simultaneous work, Müller
is also more cited than Wundt, who has only one work cited, with
two page citations. Müller, in contrast, has 3 works with 6
citations, and 4 works with 7 citations if Martin and Müller (1899)
is included. In Stevens (1951), Müller has 18 citations to Wundt's
5. It is only when the previous minimal contact with Müller's work
has disappeared that the pattern of textbook citations falls in
line with the space allotment in history of psychology books.
Fröbes 1500+ pages from the first comprehensive published
edition were the European standard for experimental psychology, and
it would be a compliment to Woodworth to call him the American
Fröbes. Even though Fröbes was Müller's dissertation student, he
had read and taught psychology comprehensively before studying with
Müller (who he chose by accident; Fröbes, 1929, p. xx), and studied
with Wundt and his assistants before returning to his Jesuit
college in Valkenburg. In this, the running page treatments of
Müller there are 3 times as many as those for Wundt. In Fröbes two
volumes, the first is what we would now consider the core of
experimental psychology is in volume I, and, for this part,
Müller's dominance is stronger than for the second volume which
contains topics such as complex feelings, aesthetics, and the self.
However, when you consider the results in the preceding table,
it is well to remember that Wundt wrote 50,000 pages to Müller's
5000; that Wundt, through the Grundzüge, wrote on every aspect of
experimental psychology, while Müller concentrated on thresholds,
memory, and color theory (which were not much cited in North
America). Thus, these baselines would certainly seem to provide
Wundt with a clear advantage. The result, however, is that with
understandable exceptions, Müller is everywhere more cited, both in
number of publications and number of pages on which citations
appear.
Doctoral and other students
It is difficult to remember an important European professor
who was nothing but Wundt's student (I think Wilhelm Wirth and
Ernst Meumann are among the most important; Külpe was Müller's
student for 3 semesters before he left for Leipzig). Indeed
Blumenthal (1985a) indicates that after 1890, Wundt was little
occupied with laboratory work, and Krohn's (1892, p. 590) review of
the laboratories mentions Külpe and Kirschmann as his assistants,
while not really mentioning him. The names of Müller's
dissertation students (Joseph Petzoldt, Victor Henri, Perla
Ephrussi, Erich Jaensch, Walter Baade, David Katz, Géza Révész, and
Georg Katona), Habilitanden (Friedrich Schumann, Narziß Ach, David
Katz, and Walter Baade) and research associates (Edgar Rubin,
Oswald Kroh, Richard Strohal) cannot be considered anything but as
a highly significant list for European psychology. (Rubin did his
dissertation with Höffding in Copenhagen, but then did further
research in Müller's "Institut" at the beginning of World War I--since he was Danish, there was no point in doing a Habilitation).
Lange (1994, p. 10) indicates that, in the period before the Nazi
takeover (1927-1933), the two authors most cited in the Zeitschrift
für Psychologie were both Doktoranden of Müller, Eric Jaensch and
David Katz.
In addition to his well-known students, Müller had 30 other
Doctoral students. His standards for doctoral work (in contrast to
Wundt) were exacting. First prepare a preliminary study in which
you learn to carry out an experiment and make equipment; then carry
out an experiment which is directed at an unresolved psychological
problem.
Organizational roles
Müller, who was virtually the founder of the Deutsche
Gesellschaft für experimentelle Psychologie (Lüer, 1991), was also
given a volume of the Zeitschrift für Psychologie as a Festschrift
in 1920 and had an entire issue of the Zeitschrift (1935) for his
Nachrüfe after he died in late 1934. At that time, the three
editors of the Zeitschrift, Schumann, Jaensch, and Kroh, could all
be considered to be his heirs. Wundt, on the other hand, seems to
have had a great resistance to professional or organizational
entanglement (Cattell, 1947, p. 437).
Müller as the methodologist of psychology
To a large extent, Müller was considered as the methodologist of psychological experimentation. He has this reputation in American psychology books. He was an extremely careful (and often extremely critical) supervisor, and he was tested for, if not a recorded subject in, each experiment carried out in his laboratory. In order to do this, he went through each laboratory setup each morning, probably more like a military officer doing inspection than a physician doing rounds. In addition, experiments carried out in his lab were the gold standard of experimental results. For Ach, and perhaps others, carrying out an experiment that had been done by Müller or by one of his students was the test of whether you could work adequately in Ach's laboratory.