## 1. Biography



Herbert Feigl was born on December 14, 1902, in the then Austrian town
of Reichenberg (nowadays Liberec, Czech Republic). Feigl's
parents were Jewish, but not religious. His father, a trained weaver,
was said to be an ardent atheist; he was a skillful and highly
ingenious textile designer and became later in his career one of the
most influential leaders in the Austrian textile industry.
Feigl's mother, who had a lifelong interest in the arts, filled
him with enthusiasm for classical music, particularly for the
symphonies of Anton Bruckner and Gustav Mahler. In 1921, Feigl began
to study mathematics, physics, and philosophy at the University of
Munich. Because of the anti-Semitic climate in Germany (and in
particular in Munich) he moved, in 1922, to the University of Vienna
where he studied under Moritz Schlick, Hans Hahn, Hans Thirring, and
Karl Buhler. In the very same year, he wrote an essay on the
philosophical significance of Einstein's theory of relativity
for which he obtained a prize in a competition (with Schlick, Ernst
von Aster and Max von Laue as referees). In 1924, Feigl became one of
the co-founders of the Vienna Circle. In 1927, he finished his
doctoral dissertation in philosophy on the relationship between chance
and law in the natural sciences. Inspired by discussions with Karl
Popper and Hans Reichenbach, Feigl, in 1929, published the monograph
*Theorie und Erfahrung in der Physik*. In the same year, he
gave a series of lectures at the Bauhaus in Dessau, between which and
the Vienna Circle there were interesting parallels in both
intellectual outlook and political approach (see Galison 1990). In
1930 Feigl married Maria Kasper, a fellow student at the University of
Vienna, and had a son (Eric Feigl).



For reasons of anti-Semitism and occupational hopelessness, Feigl, in
1930, decided to emigrate to the United States. Funded by a
Rockefeller Research Fellowship, he first stayed for eight months at
Harvard University. Together with Albert E. Blumberg he wrote the
programmatic article "Logical Positivism: A New Movement in
European Philosophy" (published in the spring of 1931 in the
*Journal of Philosophy*). Feigl's emigration plans
then became manifest.  Retrospectively, he reports:



During the spring of 1931 [...] it became clear to me that my
chances for a teaching position in an Austrian or German University
were extremely slim. True, the ever so optimistic and kindly Schlick
was convinced that I would obtain a Privatdozentur (position as a
lecturer) at the University of Vienna. But though I was Austrian by
birth, I had become a Czechoslovakian citizen after the revolution in
1918. My home was then Reichenberg (Liberec), in the Sudetenland,
where I was born and grew up, and had attended primary and secondary
schools. My parents, though thoroughly 'assimilated', were
of Jewish decent. More realistic than Schlick, I abandoned the idea of
a teaching career in Europe, and began applying in a number of
American universities. (Feigl 1981, pp. 73-4)



In advance of applying to American universities, Feigl received
letters of recommendation from Albert Einstein, Percy W. Bridgman, C.
I. Lewis, and Alfred North Whitehead. Lewis wrote in his letter of
April 14, 1931: "Dr. Feigl is one of the group - with
Carnap, Reichenbach, and Schlick - who represents the newly
formulated 'neo-positivism,' which represents what we in
America are sure to regard as the most promising of present movements
in Continental philosophy." (Quoted in Limbeck-Lilienau 2010, p.
102) Feigl himself looking back:



Three universities, Rutgers, New York University, and the State
University of Iowa, were the only ones that wanted to 'look me
over', and toward the end of May 1931 I visited all three
places. The late Dean George Kay [of the University of Iowa]
telephoned Professor Lewis long distance. As Lewis related to me, Dean
Kay asked him in detail about my qualification, character, and
personality. At the end of that (about twenty minutes!) telephone
conversation, Kay finally asked: 'Is he a Jew?' To this,
Lewis, the noble New Englander, gave the - to me unforgettable
- reply: 'I am sure I don't know, but if he is,
there is nothing disturbing about it'. (Feigl 1981, p.
74)



From 1931 to 1937 Feigl taught as a lecturer and assistant professor
at the University of Iowa. In 1937, he was granted US citizenship.
From 1938 to 1940 he served as an associate professor at the
University of Iowa. Eventually, in 1940, Feigl received a full
professorship at the University of Minnesota in Minneapolis. There he
founded in 1953 the Minnesota Center for the Philosophy of Science
which was the first center of that kind in the United States and which
is still one of the leading institutions for research in the history
and philosophy of science (further details in Neuber 2018a).



Apart from guest professorships in Berkeley (1946 and 1953), at
Columbia University (1950) and at the University of Hawai'i
(1958), Feigl had research stays in Mexico, Australia, and Austria. He
was president of the American Philosophical Association and vice
president of the American Association for the Advancement of Science.
Among the major works during his time in the United States are
writings on methodology, on the scientific realism debate and a couple
of contributions to the mind-body problem, the most well-known of
which is the essay "The 'Mental' and the
'Physical'" (1958). After his retirement in 1971,
Feigl was still active as an organizer of philosophical discussions at
his private home. He died of cancer on June 1, 1988, in
Minneapolis.


## 2. Feigl and the Vienna Circle



As already indicated, Feigl was a member of the Vienna Circle from its
very beginning. Together with Friedrich Waismann he had suggested to
Schlick the formation of an evening discussion group (see Feigl 1981,
p. 60). Schlick took over the idea and installed a Thursday evening
colloquium in the Vienna Boltzmanngasse 5, the location of the
University's Department of Mathematics. Among the co-founders of
the Circle were, besides Waismann and Feigl himself, Hans Hahn, Otto
Neurath, Olga Hahn-Neurath, Viktor Kraft, Felix Kaufmann, and the
mathematician Kurt Reidemeister. It was the latter who proposed the
reading and discussion of Ludwig Wittgenstein's *Tractatus
logico-philosophicus*. As Feigl reported in an unpublished
interview,



> 
> [t]he approximate date of the beginning of the [Vienna Circle] was
> 1924, but I do not remember whether it was in the spring or in the
> fall of that year. It was professor Kurt Reidemeister, the
> mathematician, who proposed the first reading of the Tractatus, and
> who (together with Hahn, Schlick and Neurath) was most active in that
> first exegesis. I myself had read the first publication of the
> Tractatus in Ostwald's Annalen der Naturphilosophie (1922, I
> believe), but at that time I was a very young student and I dismissed
> Wittgenstein as a most curios mixture of intuitive genius and
> schizophrenia. (Quoted from Stadler 1997, p. 233)
> 



However, the reading of Wittgenstein's *Tractatus* was
only one of a number of topics discussed within the Circle. According
to Feigl, "about 60 % of our time was devoted to the problems of
the foundation of mathematics and the rest to philosophy of science
and epistemology" (ibid.). Between 1926 and 1928 it was the
reading of (the typescript of) Rudolf Carnap's *Der logische
Aufbau der Welt* which dominated the discussion.



As for Feigl's own development, his doctoral dissertation under
Schlick's supervision should be mentioned first. Submitted in
July1927, the purpose of this study was to examine the problem of the
application of the probability calculus, hence its title "Chance
and law: an epistemological analysis of the roles of probability and
induction in the natural sciences." Heavily inspired by Edgar
Zilsel's *Das Anwendungsproblem* (1916), Feigl argued
along pragmatic (Humean) lines. His central thesis was that the
problem of induction cannot be solved by making recourse to the
probability concept. Feigl, thereby criticizing especially the point
of view defended by Hans Reichenbach, proposed instead a
'vindication' rather than a 'validation' of
inductive reasoning. Relying on a frequency interpretation of
probability, he argued that the limiting value of an infinite sequence
can only be inferred inductively, which in turn implied that
probability is dependent on induction and not *vice versa*.
Concerning the principle of induction itself, Feigl (like his teacher
Schlick) saw no other possibility than to interpret it as a pragmatic
(or operational) maxim. On the whole, however, the approach laid down
in Feigl's dissertation was, as Feigl himself later conceded
(see Feigl 1981, p. 6), severely limited by its neglect of the
simultaneous rise and development of quantum mechanics.



It was in the 1929 book *Theorie und Erfahrung in der Physik*
that Feigl reflected on the philosophical significance of quantum
mechanics. In addition he elaborated on the more general issues of
scientific explanation and the hypothetico-deductive method in theory
construction, thereby informally anticipating ideas later developed in
more detail by Karl Popper and especially by Carl Gustav Hempel. On
the programmatic level, Feigl criticized both Kantianism and
conventionalism and argued, positively, for a 'critical
realist' approach to the relationship of theory and experience
in physics. The book, which received favorable reactions by practicing
physicists such as Albert Einstein and Wolfgang Pauli, was
Feigl's only book in German language. Its exposed position with
respect to programmatic outlook Feigl retrospectively described as
follows:



> 
> Although I had been in the 'loyal opposition' in regard to
> the positivism of the Vienna Circle, I had a hard time maintaining
> against them the sort of critical realism that I had originally
> learned to adopt from Schlick's own early work [...]. Under
> the influence of Carnap and the early Wittgenstein, Schlick and
> Waismann were converted to a sort of phenomenalistic positivism during
> the middle twenties. Their brilliant and powerful arguments
> overwhelmed me temporarily. But encouraged and buttressed by the
> support of Popper, Reichenbach, and Zilsel, I regained confidence in
> my earlier realism and developed it in my first book on *Theorie
> und Erfahrung in der Physik* [...]. (Feigl 1981, pp.
> 9-10)
> 



That Schlick was converted to "phenomenalistic positivism"
might be contested (see Geymonat 1985); but, beyond the shadow of a
doubt, Feigl's realistic reconstruction of the theories of
physics had a minority status within the Vienna Circle. After his
emigration to the United States, Feigl devoted much of his work to
developing a stable realist stance.


## 3. Logical Empiricism and Scientific Realism



It is commonly supposed that logical empiricism and scientific realism
are systematically at odds. However, Feigl's diverse
contributions to the scientific realism debate just suggest the
opposite: Influenced by the early 'critical' realism of
his teacher Schlick, Feigl (like Reichenbach and Eino Kaila) argued in
terms of a reconciliation of both positions, that is, he attempted to
combine logical empiricist methods with a scientific realist account
of theoretically postulated entities (see, in this connection, also
Neuber 2012, esp. pp. 45-51, and especially Neuber 2018b, ch.
5).



To begin with, in their 1931 article "Logical Positivism: A New
Movement in European Philosophy," Feigl and Blumberg presented
the logical positivist approach as the synthesis of two
"significant traditions" (Feigl/Blumberg 1931, p. 281):
the classical "positivistic-empirical" current in European
philosophy, and the development of modern (mathematical) logic. The
most characteristic feature of the emerging "new movement"
was, according to Feigl and Blumberg, its conception of the
propositions of metaphysics as "meaningless" (ibid., p.
282). This diagnosis also pertained to Kant's account of
synthetic *a priori* judgments, the existence of which was
explicitly contested. However, it must be seen that Feigl never went
as far as to reject the analytic/synthetic distinction as such. As he
later argued against Quine, "[t]he revolt against the dualism of
the analytic and the synthetic rests on a confusion of the logical
analysis of (artificially fixed) languages with the historical
investigation of (growing, shifting natural) languages" (Feigl
1956, p. 7-8). Thus, in the logical positivist account, analytic
propositions had to be sharply distinguished from synthetic
propositions. Whereas the latter had their place in experience and
experiential science, the former belonged to logic and mathematics.
More precisely, Feigl and Blumberg agreed with Wittgenstein that
logic, by its very nature, is purely tautological. It has nothing to
do with experience, but only with the internal structure of language.
Here, they saw the principle advantage over previous, traditional,
empiricist accounts of logic and mathematics. Moreover, Feigl and
Blumberg maintained that even the concepts of the empirical sciences
are such as can be subject to a purely formal, logical,
reconstruction. Relying on a principled distinction between
"knowledge proper" (*Erkenntnis*) and objectivity,
on the one hand, and "immediate experience"
(*Erlebnis*) and subjectivity, on the other, they referred the
reader to Carnap's *Der logische Aufbau der Welt*,
thereby implying that a constitution of empirical concepts from a
single primitive relation, namely that of
"*Ahnlichkeitserinnerung*", by "purely
logical operations" (Feigl/Blumberg 1931, p. 286) was at least
in sight. The essential point in this connection was that the
propositions of empirical science were supposed to be translatable
into a series of propositions which exclusively referred to structural
features of experience, but not to the experientially given itself
(which was conceived of as completely subjective and thus
'private'). It was therefore structure which stood in the
focus of the respective reconstruction of empirical knowledge.
Knowledge, according to Feigl and Blumberg, is to be defined as
"the communicable" (ibid.) and "[w]hat knowledge
communicates is structure [...]." (ibid.)



It was just a few years later that Feigl--rather
significantly--modified his point of view. Or, as he himself
reports:



> 
> Having stereotyped myself (in the notorious fanfare article written in
> collaboration with A. E. Blumberg [...]), as a 'logical
> positivist,' the label has stuck to me ever since. As early as
> 1935, however, I abandoned the label [...] and availed myself of
> the alias 'logical empiricist.' This was triggered by a
> remark of a French philosopher at the International Congress for the
> Unity of Science in Paris (1935). He burst out at me: '*Les
> positivists, ce sont des idiots*!' (Feigl 1981, p. 38)
> 



The programmatic impact of the distinction drawn here by Feigl between
'logical positivism' and 'logical empiricism'
might be doubted (see Uebel 2013). However, in order to adequately
understand the line of Feigl's philosophical development, the
distinction is quite apt. Thus, in the first instance, it was the
liberalization of the logical positivist criterion of meaning which
caused a shift in Feigl's general philosophical outlook.
According to the early, logical positivist, conceptions of language
and science, the meaning of a proposition must be anchored in
observable facts. More precisely, the meaning of a given proposition
is entirely exhausted by its verification on a purely observational
basis. Yet it turned out, as a major consequence of the Vienna
Circle's protocol-sentence debate (see Uebel 2007), that this
criterion was far too strict. Direct verifiability was (by Carnap,
Hempel, and others) substituted through weaker criteria such as (at
least indirect) testability (see Carnap 1936/37) or confirmability and
disconfirmability (see Hempel 1935; 1945; 1950a). Nevertheless, the
logical positivists' rejection of metaphysics remained
quintessentially intact. As Feigl points out in a paper titled
"Scientific Method without Metaphysical Presuppositions"
(1954), there are two senses in which the term
'metaphysics' appears objectionable also from the
liberalized, logical empiricist, perspective; namely a) the assertion
of transcendent, i.e., in principle untestable statements, and b) the
belief in factual truths that could be validated a priori, i.e., in
complete independence of the data of observation. In both cases, the
realm of the meaningful is distinguished from these two objectionable
regions.



Another, systematically more far-reaching aspect of Feigl's
(self-ascribed) shift from logical positivism to logical empiricism
was his increasingly explicit embrace of a 'realist'
approach to science and scientific theory construction. In
Feigl's own words: "Perhaps the most important and
constructive aspect in the transition to Logical Empiricism was the
element of empirical or scientific realism that became increasingly
prominent in our views. Reichenbach and I had already opposed the
phenomenalistic reduction during the twenties. In this regard we were
closer to the views of Zilsel and Popper. We regretted that Schlick
had abandoned his early critical realism, and we tried to reinstate it
in a more defensible form." (Feigl 1981, p. 80) At another
place, Feigl indicates: "My own emancipation began in the
middle thirties and was stabilized in the forties. Studies and
teaching in the field of the philosophy of science helped me regain,
refine, and buttress my earlier realistic position. I was also greatly
encouraged by the scientific realism of Hans Reichenbach and the
realistic epistemologies of my steadfast dear friends Roy W. Sellars
and Wilfrid Sellars." (Feigl1981, p. 39)



It was as early as 1935 that Feigl, at the above quoted International
Congress for the Unity of Science in Paris, gave a talk on
"Sense and Nonsense in Scientific Realism" (see Feigl
1936; further Neuber 2011, p. 169). In 1943, then, he published a
paper titled "Logical Empiricism." There, he argued that
the term 'real' is employed with good reason (both in
daily life and in science) to designate "that which is located
in space-time and which is a link in the chains of causal
relations" (Feigl 1949, p. 16). In this sense, the reality of
atoms (and other theoretically postulated entities) is equally capable
of empirical test as the reality of rocks and trees. Accordingly,
reality should be ascribed to whatever is confirmed as having a place
in the spatiotemporal-causal system. After all,
this--realistically inspired--point of view directly emerged
from the liberalization of the logical empiricists' criterion of
meaning. It was indeed the result of the insight that "most of
our knowledge, and especially almost all of the more interesting and
important part of it, is highly indirect. It is shot through with
interpretation, construction, and inference, and consequently is
dependent on very general assumptions" (ibid., p. 14).



However, Feigl's mature conception of a synthesis of scientific
realism and logical empiricism is to be found in his 1950 article
"Existential Hypotheses" (published in *Philosophy of
Science*). There, it was *semantics* which served as the
vehicle for Feigl's promotion of the realist project. By
'semantics,' Feigl meant (in a nutshell) the formal
scrutiny of reference and truth (see Feigl 1950a, p. 36). As such, it
had nothing to do with the concrete methods of testing hypotheses.
Rather, "semantic realism," as Feigl pointed out at
another place, "is concerned only with the most abstract and
formal features of the semiotic situation" (1950b, p. 192). This
implied, in particular, that a) reference must be sharply
distinguished from evidence, and that b) truth must be sharply
distinguished from verification. It was on this basis that Feigl saw
himself in a position to avoid "the reductive fallacies of
phenomenalism" (1950a, p. 35). By the "reductive fallacies
of phenomenalism," he meant the logical constructionist accounts
of Bertrand Russell (1914) and the early Carnap (1928). In
Russell's and Carnap's view, the theoretical statements of
the empirical sciences were, at least according to Feigl,
"considered as translatable into statements concerning the data
of direct experience" (1950a, p. 35). This conception was, in
Feigl's eyes, "fallacious" because the assumption of
complete translatability was, he thought, semantically misguided.
Theoretical sentences should be invested with what Feigl called their
(so to say 'untranslatable') "surplus
meaning." This surplus meaning he considered to consist in the
"factual reference" of theoretical terms (ibid., p. 48).
More concretely, Feigl was convinced that terms like
'atom,' 'force,' or 'electromagnetic
field' cannot be reduced to purely observational terms
describing our direct experiences. Rather, theoretical terms were
supposed to refer to unobservable, mind-independent entities, so that,
for example, the referent of the term 'atom' would be real
atoms and not samples of 'logical constructions' out of
sense data (or other kinds of directly perceivable things). Therefore,
Feigl urged that "we must distinguish between the radical
empiricist's meaning of 'meaning' (i.e., epistemic
reduction) and another, more common-sensical meaning of
'meaning' (factual reference)" (ibid., p. 49).



It has (very aptly) been remarked that Feigl's "semantic
realism is an anti-reductive position" (Psillos 1999, p. 12). It
is anti-reductive insofar as the theoretical language of science is
claimed to be autonomous in relation to the observational evidence
base. Consequently, the mind-independence of the 'factual
referents' of theoretical terms seems to be secured by the very
reference relation itself: the existence of theoretical entities like
atoms is obviously implied by the independent reference of theoretical
terms like 'atom.'



Moreover, Feigl's account of factual reference is intimately
linked with the concept of truth. In general, the meaning of a
sentence consists, according to the theory proposed by Feigl, in its
truth conditions (see Feigl 1950b, p. 191 and Feigl 1981, p. 43).
These truth conditions, in turn, are treated compositionally: they
obtain when the entities to which we refer stand in the relations to
which we refer, that is, independently of the conditions of the
corresponding scenario of verification. Accordingly, relations between
the 'factual referents' of theoretical terms serve as
'truth makers' for theoretical statements. Feigl therefore
concludes that by adopting a "semantic metalanguage" (as
he could find it in the works of Tarski and the later Carnap) we are
in a position to employ "a conceptual model in which statements
as well as the states of affairs that render these statements true,
can be represented" (Feigl 1950a, p. 49).



Still, there is an important qualification in Feigl's account of
realism. This qualification has to do with the fact that Feigl takes
pains to separate his own semantic-scientific realism from traditional
metaphysical realism. By metaphysical realism, Feigl means all
attempts to systematically employ "transcendent, i.e., in
principle untestable, assertions" (Feigl 1956, p. 22). By his
own account, however, the testability or confirmability of an
assertion is the crucial criterion for its being meaningful. Feigl
writes:



> 
> No concrete existential hypothesis of ordinary life or of science is
> factually meaningful unless it is confirmable. The essential
> requirement of empiricism is thus safeguarded. But the very adoption
> of the *confirmability* criterion (in preference to the
> narrower *verifiability* criterion) allows as much realism as
> we are ever likely to warrant. (1950a, pp. 50-51)
> 



And at another place, he comments:



> 
> Semantic realism as I should like to see it understood, is free from
> the dangers of metaphysics precisely because it does *not
> prescribe* anything at all about the *nature* of the
> designata of our theoretical constructs. [...] Things are and
> will always be--as far as we can meaningfully talk about
> them--what they are confirmably *knowable* as; and it is
> up to the advance of science, not to logical and semiotic analysis, to
> tell us what things are "really" like. But it is the task
> of logical analysis to tell us by means of what rules of our language
> we describe the objects of our knowledge, and [...] what we mean
> by the surplus of the *knowable* over the *known*.
> (1950b, p. 192)
> 



It should be noted that this passage is quoted from Feigl's
reply to criticisms brought forward by his logical empiricist
colleagues Philipp Frank, Carl Gustav Hempel, and Ernest Nagel (the
context being a symposium on Feigl's "Existential
Hypotheses"). Hempel, for instance, had argued that the notion
of the reference of theoretical terms is "unnecessary"
because it "can be eliminated, by means of Feigl's own
criterion of factual reference" (Hempel 1950b, p. 173), namely
the systematic interconnections between theoretical statements on the
one hand and observations sentences on the other. In a similar vein,
Frank had objected that "after the introduction of the truth
conditions a statement in the language of 'semantical
realism' can no longer be distinguished from a statement in the
language of 'syntactical positivism'" (Frank 1950,
p. 167). Quite the same was brought forward by Nagel who argued that
by heavily relying on confirmability Feigl completely remains within
the 'received' logical positivist agenda, so that his talk
of 'realism' should be regarded as devoid of any
distinctive character. According to Nagel, "Feigl is pressing
for a distinction without a difference" (Nagel 1950, p.
179).



In order to counter these objections one would have to show how
semantics (i.e., Feigl's theory of reference and truth) and
epistemology (i.e., Feigl's insistence on confirmability) are
related to each other. There is some evidence that Feigl's
adoption of Wilfrid Sellars's idea of a 'pure
pragmatics' (see Feigl 1950a, pp. 49-50; 1981, pp.
254-255) could play the essential role in this connection.
However, Sellars's conception of a 'pure pragmatics'
is itself rather "eccentric" (Carus 2004, p. 320) and it
is fairly hard to see how, according to Feigl, a realist approach to
science could be defended on the basis of an essentially pragmatic
justification (for further details, see Neuber 2011, pp.
175-176, and especially Neuber 2017)


## 4. Analysis of the Mind-Body Problem



Feigl's treatment of the mind-body problem is his probably best
well-known--and at the same time most
controversial--contribution to philosophy. It is often lumped
together with the views of U.T. Place, J.J.C. Smart, D.M. Armstrong,
and other Australian, 'materialist,' philosophers (see,
for example Kim 1998, pp. 1-2). Indeed, both Feigl's and
the Australians' approach toward the mind-body problem share a
number of similarities. On the whole, they are both versions of a
non-dualistic (anti-Cartesian), physicalistically inspired
'identity theory.' However, there are significant
differences between the Austrian (i.e. Feigl's) and the
Australian version of the identity theory (see Stubenberg 1997).
Whereas the Australians take the physical as unproblematic and attempt
to reduce the mental to the physical, Feigl takes the mental as
unproblematic and attempts to integrate it into a sophisticated
physicalistic conception of the world.



It is important to note that Feigl's version of the identity
theory is not without precursors. It has even been argued that
"[s]een against the backdrop of nineteenth-century German and
Austrian philosophy, Feigl's approach was neither novel nor
audacious; he merely revived a tradition that had once been a
mainstream topic turned unfashionable; to be exact, he modified and
spelled out one specific traditional position" (Heidelberger
2003, p. 234). This might be exaggerated, but it can hardly be
contested that Feigl, in his treatment of the mind-body problem, was
(again) committed to the critical realist accounts of Alois Riehl (cf.
Riehl 1879, 1881, 1887; further Rod 2001) and especially of the
early (pre-Viennese) Schlick (see the entry on
 Moritz Schlick).
 As Feigl himself frequently pointed out, it was the early
Schlick's "double-knowledge" or
"double-language" theory that exerted the greatest
influence upon his own approach (see, for example, Feigl 1981, p.
288). In a nutshell, Schlick, in his *General Theory of
Knowledge* (1918; 1925), had argued that the difference of the
mental and the physical is a difference between two conceptual systems
and not a difference between two areas of reality. It was, in other
words, an epistemological rather than a metaphysical problem (cf.
Schlick 1974, p. 300). According to Schlick, the "relation
between immediately experienced reality and the physical brain
processes is [...] no longer one of causal dependency but of
simple *identity*. What we have is one and the same reality,
not 'viewed from two different sides' or
'manifesting itself in two different forms', but
designated by two different conceptual systems, the psychological and
the physical" (ibid., p. 299). It was this very line of thought
that confirmed Feigl in his conviction that "the mind-body
problem is not a pseudoproblem" (Feigl 1981, p. 349).



The essential question to be answered by an elaborated identity theory
is, in Feigl's view, the following: "[H]ow are the raw
feels related to behavioral (or neurophysiological) states?"
(1967, p. 5) By posing the question that way, Feigl excludes a
reductive solution to the mind-body problem. More precisely, he
dissociates himself from the "reductive fallacies" (1981,
p. 16) of eliminative materialism and of radical behaviorism. On the
other hand, however, Feigl is eager to demarcate his own position from
overtly--metaphysically inspired--dualistic conceptions,
such as parallelism or epiphenomenalism. He explicitly opts for a
"monistic solution" (ibid., p. 298), arguing that the
dualistic position would lead to an ungrounded "duplication of
realities" (1967, p. 94), whereas the--scientifically
well-established--principle of parsimony "does oppose the
operationistic predilection for speaking of two (or more) concepts if
the evidential facts, though completely correlated, are qualitatively
heterogeneous" (ibid.)



On the constructive side, Feigl's solution to the mind-body
problem might indeed be regarded as a direct continuation of the
earlier 'double-language' conception presented by Schlick.
Like in the case of the realism issue, Feigl attempts at a
semantically more sophisticated revision of the original Schlickian
point of view. One can even go further and say that it is the very
same terminology which is employed by Feigl in this connection. Thus,
just like in the case of realism, Feigl categorically distinguishes
the evidential (or confirmatory) basis from the factual reference (or
content) of the respective knowledge claims. Feigl writes:



> 
> The central core of the proposed solution rests upon the distinction
> between evidence and reference. No matter what indirect (behavioral)
> evidence we use for the ascription of mental states, the mental state
> ascribed is not to be confused with the evidence which only leads
> support for the ascription. (Feigl 1967, p. 99)
> 



Accordingly, it is mental states which are to be regarded as the
referents of both psychological and physical terms. More precisely,
Feigl assumes that, in the case of psychological terms, evidence is
derived from (direct) knowledge by acquaintance, whereas in the case
of physical (neurophysiological) terms evidence is derived from
(indirect) knowledge by description (see Feigl 1967, p. 94). Yet, the
referent is in both cases the same, so that we have a relation of
'referential identity,' as in the context of Gottlob
Frege's example of the terms 'morning star' and
'evening star' that differ in sense (*Sinn*), but
not in reference (*Bedeutung*), which in both cases is
identical, namely Venus (see, for this analogy, Feigl 1981, pp.
346-347). Consequently, we have two kinds of evidence for one
and the same type of events. It is for this reason that Feigl's
identity theory is committed to a dualism at the evidential basis. Or,
as Feigl puts it in "The 'Mental' and the
'Physical'":



> 
> [W]hat is *had-in-experience*, and (in the case of human
> beings) *knowable by acquaintance*, is identical with the
> object of *knowledge by description* provided first by molar
> behavior theory and this in turn is identical with what the science of
> neurophysiology *describes* (or, rather, will describe when
> sufficient progress has been achieved) as processes in the central
> nervous system, perhaps especially in the cerebral cortex. In its
> basic core this is the "double knowledge" theory held by
> many modern monistic critical realists. (1967, p. 79)
> 



In the footnote attached to this passage, Feigl refers the reader to
the views of Riehl, Schlick, Russell, and Roy Wood Sellars (among
others); and he then continues:



> 
> This view does not have the disadvantage of the Spinozistic doctrine
> of the unknown or unknowable *third* of which the mental and
> the physical are aspects. The "mental" states or events
> (in the sense of raw feels) are the referents (denotata) of the
> phenomenal terms of the language of introspection, as well as of
> certain terms of the neurophysiological language. For this reason I
> have in previous publications called my view a "double-language
> theory." (ibid., pp. 79-80)
> 



There are two peculiarities to be noticed in Feigl's version of
the double-language theory. First, it must be seen that qualia (raw
feels) are, for Feigl, the--epistemologically--*basic
reality*. On his conception, we have privileged access to this
basic reality, so that (as Feigl points out in the postscript to
"The 'Mental' and the 'Physical'")
the "egocentric account" (ibid., p. 155) must be regarded
as the most immediate mode of getting into contact with reality,
whereas "all scientific accounts [...] deal with Being only
indirectly and structurally" (ibid.; see also Feigl 1981, pp. 17
and 351). The privileged access to qualia (such as seeing red, feeling
pain, etc.) is, according to Feigl, accompanied by the use of
indexical terms (such as "here", "now",
"I", etc.) that in turn form part of a
"private" (egocentric) language and which are
systematically analyzed in the context of the metalinguistic
discipline of pure pragmatics (see Feigl 1967, p. 147). Thus, in
Feigl's view, "I must be able to know (by
'acquaintance') some phenomenal qualities and relations
(redness, between-ness, etc.) in order to 'hook' (i.e.
connect) my private language to the intersubjective language of
science" (ibid.). At the same time, he sees no problem in
describing private mental states by intersubjective scientific
(neurophysiological) terms. "Privacy," Feigl writes,
"is capable of public (intersubjective) description, and the
objects of intersubjective science can be evidenced by data of private
experience" (ibid., p. 81). After all, Feigl is convinced of the
"indispensability of a subjectivistically understood conception
of immediate (first person) experience" (Feigl 1981, p. 353),
which, on the one hand, entails a clear rejection of Ludwig
Wittgenstein's arguments against the possibility of a private
language (see Feigl 1981, p. 355), and, on the other hand, marks a
significant contrast to the Australians' strategy of
'explaining away' the phenomenal properties of mental
states (see, in this connection, Stubenberg 1997, pp. 135-136).
The possible objection that Feigl, by epistemologically privileging
qualia, runs into the trap of panpsychism can be countered by the
argument that all reality is, in fact, "at bottom
qualitative" (Stubenberg 1997, p. 143). Thus, not only mental
states, but also the diverse physical magnitudes (like mass, pressure,
gravitational field intensity, etc.) are distinguishable only by their
qualitative peculiarities (see Feigl 1967, pp. 43-44; see
further Schlick 1974, pp. 283-285). But this does not imply that
all reality is, like panpsychism would have it, intrinsically psychic.
Qualia form part of reality, but reality comprises more than only
qualia. The point is that qualia (raw feels) are, for Feigl,
epistemologically privileged as compared to ordinary objects and the
entities posited by science. "Reference to one's own
immediate experience," Feigl (in an overtly Schlickian manner)
writes, "is the (epistemological) prototype of all designations
of objects, properties or relations by the words of our
language" (1981, p. 355).



The second point to be noticed is that, according to Feigl's
version of the identity theory, the mode of *ascertainment* of
the identity of the mental (raw feels) and the physical (neural
processes) is empirical in character. Had Feigl in his first
publication on the mind-body problem in 1934 assumed that the
relationship between the mental and the physical is that of a
*logical* identity (thereby implying that the language of
psychology can be fully translated into the language of physics,
*viz.* neurophysiology), he, in his later writings, no longer
conceived of that identity as a logically necessary, but as an
empirical (contingent) kind of identity. This meant, in the first
place, that the *corroboration* of the philosophically outlined
monism had to be provided, not by philosophical analysis again, but by
the factual sciences themselves. "On the whole," Feigl
concluded:



> 
> I should think, the available evidence points with remarkable
> consistency in the direction of a system of psychology, psycho-physics
> and psychophysiology which provides for the monistic solution here
> outlined. But this is the empirical, the factual issue which
> philosophical analysis cannot decide and should not prejudge. (Feigl
> 1981, p. 298)
> 



The sort of modesty displayed in passages like the above is very
characteristic of Feigl's way of thinking. Just as in his
discussion of the realism issue, he leaves it to the factual sciences
to judge about the adequacy of his preferred philosophical position.
His methodological outlook can therefore be characterized as
"metascientific" (rather than metaphysical), in the sense
that "a comprehensive reflection on the *results* of
science as well as on the logic and epistemology of scientific
*method*" (ibid., p. 349) is aspired to. However, the
decision between global philosophical stances, like realism and
phenomenalism or, as concerns the mind-body problem, monism and
dualism cannot be decided by empirical means, but only by a
"pragmatic justification" (ibid., p. 294). In the case of
the identity theory, this pragmatic justification is, as has been
pointed out before, guided by the principle of parsimony.



Feigl's approach to the mind-body problem became subject of
extended controversy. While some authors directly contested the
identity thesis as such (see, for example, Abelson 1970 and Epstein
1973; further the replies in Grunbaum 1972 and Nathanson 1972),
others urged that Feigl should clarify his conception of the relation
of phenomenal predicates and "raw feels." Especially
Feigl's Minnesota collaborator Paul Meehl argued along these
lines, claiming that the main problem with Feigl's view stems
from semantics (see Meehl 1966; further Aune 1966). On the whole, it
can be said that identity theory was discussed from various
philosophical perspectives. That Feigl left a considerable legacy can
hardly be denied in this connection.


## 5. Writings on Value Judgment, Humanism, and Religion



Feigl's writings on practical issues like ethics, humanism, and
religion are rather less well known (but see, rather recently, the
reconstruction in Siegetsleitner 2014, ch. 11). Still, they are worth
considering, especially since they contain some interesting
applications and extensions of the logical empiricist agenda. The
all-embracing idea, though, came from the eighteenth century:
According to Feigl, "a new age of enlightenment, scientific as
well as ethical, is our most imperative need" (1981, p. 406).
Therefore, "[t]he straightforward spirit of eighteenth-century
Enlightenment (e.g. Hume, Kant) needs reviving and
'updating'" (1981, p. 399). The programmatic frame
for this 'updating' Feigl labeled "scientific
humanism" (ibid., pp. 368, 405, 408, 418)--by which he
understood the attempt at a "synthesis of the scientific
attitude with an active interest in the whole scale of human
values" (ibid., p. 368). It was this conception within which he
theorized about the relationships between ethics and logic and between
religion and empirical science.



As concerns the relationship between ethics and logic, Feigl draws a
principled distinction between two kinds of justification:
"vindication" and "validation" (see Feigl
1981, pp. 14, 256-260, 385). While validation "involves
reliance upon the principles of logic" (ibid., p. 245),
vindication has to do with the pragmatics of evaluating certain types
of behavior with respect to certain ends. Thus the latter, pragmatic,
form of justification may be called '*justificatio
actionis,'* whereas the former, logical, form of
justification may be called '*justificatio
cognitionis'* (see ibid., p. 385). Feigl's point,
then, is to show that specific ethical norms are capable of being
validated, but that general ethical principles (and the respective
ethical systems) are only capable of being vindicated. Feigl
writes:



> 
> Validation terminates with the exhibition of the norms that govern the
> realm of argument concerned. If any further question can be raised at
> all, it must be the question concerning the pragmatic justification
> (vindication) of the (act of) adoption of the validating principles.
> But this is a question of an entirely different kind. (1981, p. 386)
> 



Two things should be noted here. First, in contrast to other logical
empiricist accounts of ethics (for example, in the fist place, A.J.
Ayer's), Feigl's conception is, as has been argued (see
Kellerwessel 2010), committed to a certain form of
*cognitivism*. That means that "moral judgments are to be
reconstructed as knowledge-claims and as subject to validation (or
invalidation) by virtue of their accordance (or non-accordance) with
the supreme norms of a given ethical system" (Feigl 1981, p.
388). Accordingly, *within* such a given ethical system, moral
reasoning can be justified by the "rules of deductive and
inductive inference" (ibid., p. 385) and thus be reconstructed
along cognitive, i.e. rational, lines. However, secondly, the
respective ethical system (and its "supreme norms") itself
can only be *vindicated* by pragmatic maxims. Thus, Feigl
allows the possibility of a "pragmatic justification of the
adoption of an alternative frame" (ibid., p. 386), thereby
implying that there exists a plurality of alternative ethical systems.
It is interesting to see that Feigl refers the reader here to
Carnap's distinction between "internal" and
"external" questions in his 1950 "Empiricism,
Semantics, and Ontology" (see Feigl 1981, p. 391, Fn. 3; see
further Feigl 1981, pp. 13-14). Indeed, there is a deep analogy
between this distinction drawn by Carnap and Feigl's distinction
between the validation *within* an ethical system and the
vindication *of* the ethical system (and its supreme norms)
itself. Furthermore, it can be stated that Feigl, in his pragmatic
argument for scientific *realism*, was also inspired by
Carnap's distinction and its relativization of the ontological
dimension (see, for further details, Neuber 2011, p. 179).



On the whole, scientific humanism is designed to avoid the extremes.
It qualifies, according to Feigl, as "a tenable middle ground
between the relativists and the absolutists in morals" (1981, p.
417). In contrast to relativism, it is assumed that certain basic
human values, such as justice, fairness or equality, are universally
applicable. However, in contrast to (for instance, Kantian)
absolutism, it is at the same time assumed that those values are
related to human interests and thus empirically variable. They
"may have come out of the natural development of human beings in
the social context" (ibid., p. 420), and they can only be
justified pragmatically (by way of vindication). But, Feigl maintains,
that does not make them arbitrary: "If we dig deeper into human
nature we find that in some social contexts certain moral ideals
inevitably work themselves out" (ibid., p. 418). In the
"age of scientific enlightenment" (ibid., p. 420) an
ethically disinterested or even cynical view of the world is therefore
out of place: "Psychology points in the direction of human needs
and interests that must be satisfied. And in the social context,
certain traffic rules simply have to be obeyed if we are to survive as
a society. Thus we have ideals of justice and equality."
(ibid.)



Feigl's broadly naturalistic view of human beings and the world,
together with the (liberalized) logical empiricist criterion of
meaning, entails a constructive but at the same time critical approach
toward religion. To be sure, Feigl did not deny the existence of
religious experiences (see, for example, Feigl 1981, 399-400).
But he did not "see [...] the slightest reason for
accepting *any* sort of theology" (ibid., p. 399).
Although some of the dogmas of theology were seen by Feigl as
"perfectly meaningful" (ibid., p. 13), he conceived of
them as being false (or as being extremely unlikely). The option of a
"demythologized" (or modernized) theology (Tillich,
Bultmann, Bonhoeffer, and others) is, Feigl further maintained,
"no longer a theology at all; it reduces to a moral message,
formulated by the use of allegorical, but essentially exhorting,
consoling, edifying, or fortifying language" (ibid., p. 406). By
accepting scientific humanism, on the other hand, we are, according to
Feigl, in a position to "adopt an ethics without supernatural
foundation or supernatural sanctions" (ibid., p. 405). Religious
experiences, in turn, are then explainable in purely naturalistic
terms. They do not serve as the basis of scientific or everyday
explanation of human behavior. Rather, they are themselves
*subject* of scientific explanation. Or, in Feigl's own
words: "[W]e do not need the theistic kind of reasoning in order
to account for the phenomenon of religious experience. The influence
of the cultural and moral traditions as well as psychology can provide
a very plausible naturalistic explanation of religious experience. As
Voltaire once put it, if God didn't exist, he would have to be
invented." (ibid., pp. 415-416)



Three further points concerning Feigl's scientific humanism call
for comment. First, Feigl's early affiliation with American
Unitarianism; second, his involvement in the American Humanist
Association; third, the background to his plea for scientific humanism
in Roy Wood Sellars' contributions in that field.



On the first point, suffice it to mention that Feigl served as
president of the Men's Club of the First Unitarian Church in
Iowa City as early as 1937-38 and that he still gave talks at the
First Unitarian Society of Minneapolis in the late 1950s. Unitarian
ideals were values such as individual freedom, democratic processes in
human relations, and universal brotherhood, undivided by nations,
race, or creed.



These ideals came very close to those of the American Humanist
Association, which was founded in 1941. In 1944 Feigl was elected
assistant secretary of the Association. In retrospect, he writes:




[O]ur attitude toward theology and religion was that of the naturalist
or scientific humanists. Indeed, several of us found in the general
position of the American Humanist Association an ideology that seemed
very similar to our basic philosophical attitude. If, as most
humanists prefer, 'religion' is not connected with any
theology whatever, then a deep commitment to such human values as
basic and equal rights, the civil liberties, the ideal of a peaceful
and harmonious world community, may well be said to be the religion of
the humanists - and of the positivists. (Feigl 1981, pp.
78-79)



By 'us,' Feigl meant the emigrated logical empiricists.
Philipp Frank, in particular, also championed the humanist idea (see
Frank 2021). 



As for the influence of Roy Wood Sellars, the first thing to note is
that Sellars as early as 1918 had published a book titled *The Next
Step in Religion*. In the preface to that book, Sellars made it
clear that "the deepest spiritual life has always concerned
itself with the appreciation and maintenance of values. He who
acknowledges, and wishes to further, human values cannot be said to be
irreligious or unspiritual" (Sellars 1918, Foreword). Moreover,
Sellars pointed out: "Such attitudes and expectations as prayer,
ritual, worship, immortality, providence, are expressions of the
pre-scientific view of the world. But as man partly outgrows, partly
learns to reject the primitive thought of the world, this perspective
and these elements will drop from religion." (p. 6) On this
basis, religion is redefined as "*loyalty to the values of
life"* (p. 7). In fact, Sellars' approach is deeply
rooted in an appreciation of the progress of science (see esp. Sellars
1918, ch. XVI) and thus comes quite close to Feigl's
understanding of what he called scientific humanism. Moreover, Feigl
had certainly read the *Humanist Manifesto*, which Sellars,
together with Raymond B. Bragg, had co-edited in 1933 (see Kurtz
1973). As late as 1980, Feigl (like Willard von Orman Quine, A. J.
Ayer, and Sidney Hook) signed the *Secular Humanist
Declaration* of the *Council for Democratic and Secular
Humanism* (see Kurtz 1983).



More recently, a view very close to Feigl's scientific humanism
has been advocated by Ronald Dworkin, according to whom
"religion is deeper than God" (Dworkin 2013:1) and the
religious attitude "accepts the full, independent reality of
values" (10). Like Feigl and Sellars, Dworkin views science as a
paradigm for promoting human values.


## 6. Feigl and Twentieth-Century Analytical Philosophy



Feigl's role in the development of twentieth-century analytical
philosophy is not to be underrated. His 1950 article on
"Existential Hypotheses" can, as has been argued (cf.
Neuber 2011), be regarded as a ground-breaking contribution to the
debate over scientific realism within the analytical tradition. In
particular his focusing on the semantic notions of reference and truth
turned out as instructive for the following development, as it is
represented in the (programmatically diverse) writings of Richard
Boyd, Larry Laudan, and specifically Hilary Putnam. In recent times,
the attempt has been made to revive Feigl's point of view by
systematically exploiting the idea of "choosing the realist
framework" (see Psillos 2011). Similarly, Feigl's analysis
of the mind-body problem exerted remarkable influence on the
philosophical discourse of the second half of the twentieth century.
Thus, according to Jaegwon Kim, "it was the papers by Smart and
Feigl that introduced the mind-body problem as mainstream metaphysical
Problematik of analytical philosophy, and launched the debate that has
continued to this day" (Kim 1998, p. 1). To be sure, alternative
approaches, such as Putnam's 'functionalism' or
Donald Davidson's 'anomalous monism' came up quite
early in the discussion. Nevertheless, Feigl's (and
Smart's) account "helped set basic parameters and
constraints for the debates that were to come--a set of broadly
physicalist assumptions and aspirations that still guide and constrain
our thinking today" (ibid., p. 2)



Besides these contributions to the theoretical discourse, Feigl played
an important role at the institutional level. He not only founded and
headed the Minnesota Center for Philosophy of Science, but he also, in
1949, founded and co-edited the (still existing) journal
*Philosophical Studies* and, in 1956, the series *Minnesota
Studies in the Philosophy of Science*. Moreover, he edited such
standard setting volumes as *Readings in Philosophical
Analysis* (1949, together with Wilfrid Sellars) and *Readings
in the Philosophy of Science* (1953, together with May Brodbeck).
Furthermore, it should be emphasized that Feigl, together with Paul
Meehl, energetically promoted the revalorization of
*psychology* as a serious academic discipline. The Minnesota
Center was an extremely influential forum in this connection (for
further details, see Smith 1986).



Being a scientific philosopher *par excellence*, Feigl once
declared:



> 
> [T]here is no sharp line of demarcation between (good) science and
> (clearheaded) philosophy. Every major scientific advance involves
> revisions of our conceptual frameworks; and doing philosophy in our
> days and age without regard to the problems and results of the
> sciences is--to put it mildly--intellectually unprofitable,
> if not irresponsible. (1967, p. 137)
> 



This diagnosis, though provocative, is still accurate today.