Carnap, the Left Vienna Circle and Neopositivist Anti-Metaphysics

thomas.uebel@man.ac.uk

The barely ten years that Rudolf Carnap lived and taught in Vienna and Prague extended from the completion of the Aufbau through the trials of the Logical Syntax programme to his rebirth as a semanticist in what came to be “Testability and Meaning”.  Setting out for exile in America, Carnap emerged from this period a wisened firebrand.  It may easily appear as if he left behind not only the confrontational rhetoric that better fitted the ever more desperate cultural and political struggles in Central Europe, but also the naïve radicalism of his Vienna Circle colleagues.  I wish to argue for a different conclusion.  Wisened Carnap certainly was, but no less radical.  The old programme—which never was that naïve to begin with—was refined but not abandoned.  To see the continuity, we must place Carnap in the right context and identify the correct motive of the early radicalism. I will try to do so here with reference to the so-called left Vienna Circle and the famous if notorious neopositivist critique of metaphysics.

1.   Carnap and the Left Vienna Circle

The term ‘left Vienna Circle’ here denotes the group of Hans Hahn, Philipp Frank, Otto Neurath and Carnap.  That within the Vienna Circle around Moritz Schlick, these four may be picked out together as a unit is suggested by a number of facts.  To start with, the terms picks out Carnap, Hahn and Neurath, the three authors of Scientific World Conception. The Vienna Circle, the manifesto which alienated many, including Schlick to whom it was dedicated, with its occasionally overtly political associations.  That Frank may be counted into this group as well is suggested, amongst other things, by the fact that he organised, through his Institute of Physics at the German University of Prague, the conference-within-a-conference at the 1929 Prague Congress of German physicists and mathematicians (Frank 1930b; 1949b [1949a, 40]), at which the Vienna Circle, together with the Berlin Society for Empirical Philosophy, first presented itself to the wider public and unveiled its manifesto.  In addition Frank also presented the Circle’s philosophy of science in an opening address to the Congress as a whole (1929/30).  In word and deed, he must count as a co-conspirator.

1.1	Now why call this group by the term ‘left Vienna Circle’?  I follow historical precedent.  Carnap brought a phrase very much like it to wider attention.  In his autobiography he wrote:  

“The next step in the development of our conception concerned the nature of the knowledge of singular facts in the physical world.  Neurath had always rejected the alleged rock bottom of knowledge ... Thus some of us, especially Neurath, Hahn and I, came to the conclusion that we had to look for a more liberal criterion of significance than verifiability.  This group was sometimes called the left wing of the Vienna Circle, in contrast to the more conservative right wing, chiefly represented by Schlick and Waismann, who remained in personal contact with Wittgenstein and were inclined to maintain his views and formulations.”  (1963, 57)

Carnap used the term ‘left wing of the Vienna Circle’ to denote the group of Hahn, Neurath and Carnap in their philosophical capacity of opposing Schlick and Waismann, the “conservative right wing”, on the issue of retaining Wittgensteinian views, here strict verifiability, already early on.  A contemporary report of Frank’s resolute opposition to Waismann’s Wittgensteinianism in a meeting of the Circle in early 1935 makes plain that, especially under this description, Frank belonged to this “left wing” as well.
	But Carnap’s retrospective use of the term ‘left wing’ was not the first.  Neurath used the term and related ones several times in correspondence with Carnap in the years 1932 and 1933: “I’d prefer it if you as a centrist tending towards the left wing would give up the ‘protocol statements without confirmation’ and the parallel of ‘intersubjective’ and ‘monologising’ languages etc. and would represent the the Vienna Circle alongside those who have no truck with Wittgensteinian metaphysics…”  Subsequently, Neurath singled out “the group: Carnap, Frank, Hahn, Neurath” and even projected a “community consisting of Frank, Hahn, Carnap, Neurath and some younger people, all working on unified science”.  In the following year Neurath remarked to Carnap in a similar spirit on “the unified science group” and later on the “eternal quartet”—clearly meaning the group Carnap, Frank, Hahn and Neurath in opposition to the “Schlick sect”.  
	In their correspondence, Carnap did not use the term ‘left wing’ or its cognates.  This suggests it was Neurath’s use which Carnap picked up in his autobiography, employing it to describe the emergence of the philosophical factions in the Circle which were fully established by the time Neurath coined the term.

1.2	So much for the origin of the term; what about its descriptive content?  Prominently, but not primarily, it was suggested by their shared political beliefs.  Importantly, it was also meant to indicate—and Carnap used it in this capacity—their shared philosophical doctrines and approaches to philosophical problems as evidenced in the discussions of the Circle.  Against the background of agreement on basic tenets of neopositivism, it was they who in the Circle argued for the rejection of Wittgenstein’s strictures on meaningfulness and against metalinguistic discourse and it was also they who came to reject all foundationalist ploys in philosophy.  (Needless to say, enough topics of disagreement remained amongst them!)
Of course, Karl Menger (the son of the economist Carl and the first star student of Hahn’s) shared at least some of these philosophical proclivities, but what distinguished him even then and set him apart (soon also quasi-institutionally through his Mathematische Kolloquium) were his precisely liberal politics and his unpolitical conception of philosophy (in this he resembled Schlick).  When Neurath, Carnap and Hahn, as authors of the Vienna Circle’s manifesto of 1929, delighted in the “inner link” of the scientific world-conception and “efforts to restructure economic and social relations”, Menger objected, like Schlick, but in addition even ceased to consider himself a member of the Circle. 
	Some readers of the manifesto have wondered whether, in effect, Menger and Schlick (and Gödel) weren’t right to do so.  What “inner link” might connect fact-based scientific philosophy to value-laden political partisanship?  What prompted the conviction that these “attitudes towards questions of life are more closely related to the scientific world-conception than might at first glance appear from a purely theoretical point of view” (1929 [1973, 304]) is the view that, as Neurath put it, “doctrines free from metaphysics are also spreading and are gaining more and more ground as a new ‘superstructure’ of the changing economic ‘substructure’ of our time” (1932a [1983, 90]).
	Characteristic for the left Vienna Circle therefore was not a certain ‘mix’ of politics and philosophy, but a conception, in a larger framework, of philosophy’s relation to ongoing changes in the economic basis of society.  Officially, physicalism was an integral part of the superstructure of the coming social order.  The rather counterfactual nature of this supposition was admitted by Neurath when he wrote to Carnap in early 1933: “when will the substructure finally join our superstructure?”  One cannot help but wonder, then, just how sincere previous affirmations of historical materialism were meant to be.  Still, there remained their repeated stress, in the manifesto and elsewhere, that while socially mystifying metaphysics may appear to be on the ascendence again it was vigorously opposed by the sobriety of the scientific world conception.
	All members of the left Vienna Circle viewed philosophy to be of critical relevance to the ongoing socio-historical change towards socialism.  Beyond this, however, there emerged also considerable differences as to whether philosophy should itself be responsive to political demands: Neurath may have been prepared to concede this, but Carnap was adamantly opposed.  The shared minimal position was that an individual’s practice of the scientific world-conception places her amidst the socio-political struggles being fought, even though the work itself may remain unpolitical, but that an individual’s philosophical work also can contribute to these struggles in a direct fashion, if she so desires (and that even then different degrees of involvement were possible).  That, as the manifesto had it, “the scientific world-conception serves life” was a choice exercised by the authors of the manifesto and their supporters; that “life receives it”, meanwhile, was a short-lived but deeply cherished empirical truth for them (1929 [1973, 318]).  
So the broad political associations of the term ‘left Vienna Circle’ can be taken to have been fully intended by Neurath and Carnap.  But can we be more specific?  What was the conceptual content of this “inner link” between the scientific world conception and the noted social movements?  Apparently more was invoked than contingent political sympathies.
The keyword to characterize the focus of their common philosophical involvement in politics in the broadest sense is “bewusste Lebensgestaltung”, the conscious structuring of life.  This credo not only dominated the ideologically diffuse and ‘schwärmerisch’ pre-World War Jugendbewegung in which the young Carnap had been active, but importantly also characterised the distinctly socialist and politically concrete attitude of the activists of Red Vienna.  Carnap’s Preface of the first edition of the Aufbau pays hommage to this theme.  

“We feel that there is an inner kinship between the attitude on which our philosophical work is founded and the intellectual attitude which currently manifests itself in entirely different walks of life; we feel this orientation in artistic movements, especially in architecture, and in movements which strive for meaningful forms of personal and collective life, of education, and of external organisations in general.  We feel all around us the same basic orientation, the same style of thinking and doing.  It is an orientation which demands clarity everywhere, but which realizes that the fabric of life can never quite be comprehended.  I makes us pay careful attention to detail and at the same time recognizes the great lines which run through the whole.  It is an orientation which acknowledges the bonds which tie people together, but at the same time strives for free development of the individual.  Our work is carried by the faith that this attitude will win the future.”  (1928 [1967, xviii, trans. altered]) 

It surely says something about the academic establishment and the strongly polarised climate of the first republics in Germany and Austria that these (still fairly guarded) lines were considered scandalous and Carnap himself came to hold them responsible for his lack of academic advancement.
	Yet it was like-mindedness on just these points that Carnap found on the left wing of the Circle (and only there).  To see this, compare this paragraph with relevant passages from the collaborative manifesto, with the still more explicitly party-political last two paragraphs of Neurath’s Lebensgestaltung und Klassenkampf, with relevant but again more oblique passages of the Preface to Frank’s Kausalgesetz, and finally with the concluding paragraph of Hahn’s paper at the 1929 Prague conference: 

“The true expression of our time — a time of organizations with their stable structures owing their stability only to individual efforts, a time of rationalization in industry operating within a well-defined system by taking account of the smallest detail, a time of objectivity [Sachlichkeit] in architecture and the applied arts — the true expression of this time is the scientific world-conception with its dedicated, careful and detailed observations of the given, its cautious step-by-step logical constructions, and its plain language whose one and only task is to say clearly what is to be said.” (1930 [1980, 30], trans. altered).

Importantly, this like-mindedness of the members of the left Vienna Circle concerned their conception—which they thought was shared by the entire Circle—of the nature of the philosophical project in which they were engaged: the provision of conceptual tools for the workshop of ‘life’. 

“The Vienna Circle believes that in collaborating with the Ernst Mach Society it fulfills a demand of the day: we have to fashion intellectual tools for everyday life, for the daily life of the scholar but also for the daily life of all those who in some way join in working at the conscious re-shaping of life.”  (Carnap/Hahn/Neurath 1929 [1973, 305])

Clearly, even those who, “glad of solitude”, labour on “the icy slopes of logic” (ibid., 317) may make valuable contributions here!  Carnap’s well-known engineering conception is of a piece with the left Circle’s attitude to and approach towards philosophy.  However abstract, it has a practical dimension: linguistic proposals allow reconceptualisations of recalcitrant cognitive phenomena—in science and in ‘life’. 

1.3	So the left Circle provided an ‘ideological’ home for Carnap; yet what else did it do for him?  Once we grant that Carnap was philosophically very much his own man, we must be careful in attributing influence to other philosophers such that their views were simply adopted by Carnap.  It is safer and suffices for delineating the intellectual field in which he operated that we speak of other philosophers having a somewhat more diffuse impact on him, namely, by confronting him with certain questions and problems, not necessarily by impressing him with their proposed solutions.  If there then resulted a convergence of views, all the better.
	In this sense there can be little doubt of the importance of the left Vienna Circle to Carnap.  While not initiated there, Carnap’s democratic socialist beliefs—still professed in his American years (1963, 83)—were certainly confirmed in the left Vienna Circle.  Yet philosophically as well the left Vienna Circle impacted strongly on Carnap.  It is with Hahn, Frank and Neurath that Carnap shared his anti-foundationalist and constructionalist attitude towards philosophy.  At a minimum, they provided a sympathetically critical environment for his developing ideas on these counts.  To establish this it is only required to point to pertinent conceptions by members of the left wing conceived independently of and before Carnap but developed in discussion with him.  (To establish that at certain points his colleagues provided even more would require still further evidence, of course.)
	Part of this story is already well-known under a different description, but it deserves to be considered under the present heading as well.  This is Neurath’s opposition to Carnap’s methodological solipsism in the so-called protocol sentence debate about the evidential base of empirical science that provoked Carnap’s epistemological anti-foundationalism in 1932.  Beyond this, there are still other, less well-known aspects of the impact of the left Vienna Circle on Carnap that are worth considering.  Here one might mention that there seems to be a case to be made that also in Carnap’s epistemology of formal science, again in his overcoming of the need for traditional foundations, clear affinities are discernible with views developed on the left wing of the Circle in the early 1930s.  Then there is the intriguing possibility that complementary to their epistemological anti-foundationalism the members of the left Vienna Circle also shared a distinctive understanding of the anti-metaphysics which all early logical empiricists professed.  To assess this is my topic here.
	The pay-off, it is hoped, is twofold: historical and doctrinal.  The historical dimension emerges once we consider who the left Vienna Circle is, minus Carnap: the former so-called first Vienna Circle, a philosophical discussion round of the years 1907-12 which included Hahn, Frank and Neurath, then post-docs and young lecturers in their respectives sciences (mathematics, physics and economics).  This group presented an important Austrian counterpoint to the recently rediscovered neo-Kantian influences on the Vienna Circle.  With regard to the issue of metaphysics, however, it seems that between them and Carnap a certain trend towards convergence obtained from the start.  Pursuing this lead with regard to the vexing question of what to make of the more-or-less militant anti-metaphysics of the Vienna Circle in general, we are led,  doctrinally speaking, to a suggestion that steers the interpretation of Carnap’s mature left wing version of it between the extremes of absurdity and harmlessness and promises to link it to current concerns.  

2.  Carnap’s Anti-Metaphysics:  An Interpretive Proposal

As the manifesto put it, the Vienna Circle envisaged a “science free of metaphysics” (1929 [1973, 305]).  This was neither an uncontroversial aim in their day nor has it proved to be an unproblematical project since.

2.1	To be noted here immediately is that the Vienna Circle’s efforts generally, from either wing, did not, in the long run, finish off metaphysics at all—witness the contemporary debates about scientific realism.  (As it happens, Neurath feared as much, speaking of the dangers of a new “Metaphysica modo logico demonstrata” (1935c [1981, 701].)  Instead, analytic metaphysics owes its own respectability precisely to the failure of anti-metaphysical neopositivism to prove its point.  The very impossibility to give an airtight formal definition of some version or development of the verification criterion is nowadays held to have spelt the end of the entire demarcation programme of logical empiricism. 
	Yet was the Circle’s anti-metaphysics really tied up that closely with verificationism?  On this point, as already noted, Neurath, Hahn and Carnap clearly differed from Schlick.  Hahn remarked in lectures given in the spring of 1932, that “Mach’s requirement that all propositions containing unconstitutable terms”—irreducible to terms for observables—“be removed from science cannot be carried out: ... the whole of science would collapse.”  The reason was that “[t]he term ‘all’ is .. unconstitutable, and hence every law of nature is a proposition that cannot in principle be confirmed by observation”. Consequently, Hahn admitted indirect verification: “Thus the introduction of unconstitutable terms does not in itself amount to metaphysics; it is indispensible to science, and it is perfectly legitimate if those terms are accompanied with directions for their use, following which we can obtain from propositions which contain them other propositions which no longer contain them and which are verifiable by observation.” (1933 [1987, 40-41])  What Carnap later called the “liberalization of empiricism” (1963, 56) was already in progress here.
	The first point then is that the left Vienna Circle’s anti-metaphysics is not rendered obsolete by reliance on an unduly strict reading of the verificationist meaning criterion.  Carnap likewise did not accept Wittgenstein’s strictures on the intepretation of universally quantified hypotheses; that, beyond this, also naive falsificationism fails should not have surprised anybody after Duhem, of course, and Neurath’s stress on these points in his critique of Popper’s Logik der Forschung accordingly did not render his attitude any less anti-metaphysical.  The problem, of course, is that no formal criterion for empirical meaningfulness of any sort is available.  Here Neurath may have been more sanguine than others; already in 1934 he declared: “By sharp criticism one can hope to remove only some coarse errors and certain coarse nonsense; much remains indeterminate at first, though one cannot do without it. One’s back is never completely free, and working with ‘dubious’ statements has to be learnt.” (1935a [1983, 118], trans. amended)  Or as he put it in his correspondence: “Logic provides necessary but not sufficient protection.”
Yet however non-formalist and exemplar-based Neurath’s own empiricist meaning criterion may have been, his objections to metaphysics nevertheless were clearly epistemological: metaphysical claims were unjustifiable in principle. “I like to use the word ‘metaphysics’”, he once told an exasperated Carnap, “when I am confronted with a view which is supported by the tendency to fomulate uncontrollable assertions. The precise differentiation which you so much favour is never really possible, since one has to consider also their use.”  We may heartily agree, but this does not make the problem go away: can the principled opposition to metaphysics be based solely on such inevitably rough-and-ready criteria? 
	At best then, it seems, the failure of formal meaning-criteria leads us to conclude that either, as with Neurath, particularist reasoning seeks to support universalist claims, or, as with Hahn and Carnap, a demarcation programme is instantiated whose most central distinction cannot be made out. 

2.2	Confronted with contemporary incredulities, we are prompted to ask again just what was at issue when the authors of the Circle’s manifesto declared the death of metaphysics.  Was it perhaps merely the rejection of a speculative metaphysics, which claims insight into the essence of things that forever remains closed to mere science?  This seems to be what Carnap has in mind when he retrospectively declared about the term ‘metaphysics’ that it was used in his “Elimination of Metaphysics” “for the field of alleged knowledge of the essence of things which transcends the realm of the empirically founded, inductive science,  Metaphysics in this sense includes systems like those of Fichte, Schelling, Hegel, Bergson, Heidegger. But it does not include endeavours towards a synthesis and generalisation of the results of the various sciences.” (1932 [1959: 80]). Such a ‘normalising’ interpretation renders it easier to reestablish a connection between the Circle’s and contemporary work, to be sure.  The price of this strategy, however, is to ‘externalise’ their anti-metaphysical militance and so to ‘pathologise’ it once more.
	Now it is true to say that the Circle’s opposition against the school philosophy of its day does in some part amount to a self-conscious positioning in the academic and cultural politics of their time.  On the one hand, it allowed them (at least for a while) to dismiss even serious competitor philosophies of science like those of Cassirer for their Kantian legacy, while, on the other hand, it highlighted their defense of the Enlightenment legacy in the darkening general intellectual climate of Central Europe.  
	Still, such academic positioning does not exhaust the cognitive content of their opposition against metaphysics, nor does the opposition against the metaphysics of essences do so.  For still in that retrospective mode of 1957, Carnap reaffirmed his sceptical attitude of the cognitive meaningfulness of “the affirmative and negative theses concerning the reality of the external world” as well as “the ontological theses about the reality or unreality of abstract entities” (ibid., 81).  In his autobiography he resisted attempts by Feigl to recruit him in the service of the mind-body identity theory: 

“It seems preferable to me to formulate the question in the metalanguage, not as a factual question about the world, but as a question concerning the choice of a language form. … Those facts which Feigl proposes as evidence for the identity view are perhaps better regarded as reasons for preferring a monistic language…  To sum up, I am willing to call my position an identity conception in the following sense: in agreement with Feigl I prefer the monistsic language and like him I believe that the evidence available today provides good reasons for the assumption that this language will also function well in the future.” (1963, 885-6).

Since not only speculative metaphysics, but also scientific realism are rejected, the question inevitably reemerges whether some form of sensualist reductionism was not still in play after all.  Against this, however, we have the clear testimony of Carnap’s epistemological holism which found its expression already in his Logical Syntax of 1934 (§82): he granted only gradual differences between the empirical groundedness of theoretical and observational statements.  One might perhaps be tempted to ascribe to Carnap the defense of a form of structural realism that stops short of entity realism, but even as a structural realist Carnap would be involved in the realism debate—which, if we are to take him by his word, he wished to leave behind altogether.  So what are we to make of Carnap’s neither-realism-nor-anti-realism stance?  His fastidiousness only compounds our perplexity.

2.3	It must be remembered that the Vienna Circle’s project was not only the provision of a new conception of scientific knowledge, but also of a new conception of philosophy itself.  (Concerning this too, both wings of the Circle had different ideas and even on the left wing differences emerged in time.)  In practical terms this meant that in their philosophy they were prepared to employ new analytical tools and radically altered philosophical concepts.  The ‘new’ logic of Frege and Russell provides the most striking example of the former; for our purposes, we must focus on the latter, terms of philosophical analysis that were radically revaluated and/or reinterpreted.
	Here it is helpful to recall that Carnap did not understand Tarski’s theory of truth as a correspondence theory.  Therein, in his non-correspondentism, lies not only a continuity between his pre-semantic syntactic and his later semantic phase, but also, I’d like to suggest, the key to his and, to some extent, the entire left Vienna Circle’s understanding of their anti-metaphysical campaign.  The metaphysics they attacked, besides the supra-scientific essentialism of old, was the correspondence conception of truth and of knowledge: realism (as well as, derivatively, their contrapositives: coherence truth and idealism).  
	The advantage of this reading is obvious, I hope.  With this interpretation the opposition to metaphysics—which appears more than severely weakened by the failure of the formalist meaning criterion but apparently was not taken to be undermined thereby by (the surviving) members of the left Vienna Circle—receives principled philosophical support.   Moreover, the relevance of Viennese anti-metaphysics is retained: the correspondence theory of truth remains, after all, controversial even in contemporary analytical philosophy.
	Can this interpretation be made to work?  Note first that Carnap’s first advocacy of the semantic conception of truth, at the 1935 Paris Congress on the Unity of Science, explictly discussed previous misgivings about the notion and noted that these had led to the term ‘true’ being misused in the sense of ‘confirmed’.  Less explicitly, Carnap rejected the tendency of some Polish logicians to label the semantic conception ‘absolute’ in the sense of Twardowski and instead noted that what accounted for the truth of a statement was not only the way the world is but also the structure and concepts of the language used.  His non-correspondentist inclination shines through further in his rejection of ‘comparisons’ of statements with facts (1936, 18, 22, 21 [1949, 119, 126, 125]).  Secondly, in the soon-started but long-lasting debate in his correspondence with Neurath about the admissability of truth talk into empiricism Carnap stressed again and again that the semantic conception did not commit one to Aristotelian metaphysics as Neurath feared.
	But we need not rely on hints and private remarks.  In his contributed volume to the Encyclopedia of Unified Science, Carnap stated: “Since to know the truth conditions of a sentence is to know what is asserted by it, the given semantical rules determine for every sentence of [a constructed language] what it asserts—in usual terms its ‘meaning’—or, in other words, how it is to be translated into English.” (1939, 10)  In his Studies in Semantics, Carnap made his disquotational understanding of truth explicit: “we use the term here in such a sense that to assert that a sentence is true means the same as to assert the sentence itself” (1942, 26).  In Meaning and Necessity, Carnap declared the “rules of truth” to be rules of disquotation: “We presuppose that a statement in [the meta-language] M saying that a certain sentence S1 is true means the same as the translation of this sentence [into the metalanguage].” (1947, 6)  Carnap was happy, it seems, to return to what he must have thought of as a version of his teacher Frege’s disquotationalism.
	Note also that this interpretation does not require that we read Carnap’s anti-correspondentism as clearly realised from the start.  As I noted above, Carnap sharply distinguished truth and confirmation only by 1935 and preferred the semantic conception as explication of the former only from then onward. Among those who fell under his censure for confusing truth and confirmation were not only Neurath (and Hahn and Frank, as we shall see), but also his earlier self.  Preceding his simple non-use of the notion of truth as applicable to synthetic sentences in his Logical Syntax, Carnap himself still happily conflated talk of truth-conditions and verification conditions in his earlier “Elimination of Metaphysics”:

“Let ‘a’ be any word and ‘S(a)’ the elementary sentence in which it occurs.  Then the sufficient and necessary condition for ‘a’ being meaningful may be given by each of the following formulations, which ultimately say the same thing:  1. The empirical criteria for ‘a’ are known.  2. It has been stipulated from what protocol sentences ‘S(a)’ is deducible.  3. The truth-conditions for ‘S(a)’ are fixed.  4. The method of verification of ‘S(a)’ is known.”  (1932 [1959, 63]).  

One way of making sense of the conflation of truth- and verification conditions, of course, is to read it as a flawed way of rejecting correspondence truth.
	What is metaphysical for Carnap, so we can summarise, is not only the attempt to discern supra-scientific essences, but also a certain conception of truth and scientific knowledge.  Since the project of reconceptualising knowledge is closely related to the critique of metaphysics, we can derive from the latter a negative characterisation of the aim of the former.  Scientific knowledge is not a picturing of the world as it really is, truth is not correspondence.  In this anti-correspondentism Carnap and his colleagues on the left wing of the Circle were united as they were on nothing else.  I suggest that it be regarded as the philosophical core of not only Carnap’s anti-metaphysical animus, but of that of the entire left wing.  This contextualisation of Carnap’s anti-metaphysics opens a helpful perspective on its wider context and overarching intent which Carnap himself hardly ever addressed.

3.   Anti-Correspondentism in Neurath, Hahn and Frank

To show that the anti-metaphysics of Hahn, Frank and Neurath are also best interpreted as at core anti-correspondentist—rather than merely verificationist—I briefly outline their instrumentalism and review their unhappy pronouncements on truth.  The I return to the bigger picture of the left Vienna Circle’s anti-correspondentism.

3.1	Carnap never stopped to spell out his preferred conception of knowledge.  For that we may turn to hints from his colleagues on the left wing of the Circle.  Their remarks provide a fitting background to the interpretation of Carnap’s anti-metaphysics just developed. 
	Neurath wrote in in connection with his own attack on correspondence truth:  “Our thinking is a tool, it depends on social and historical conditions.  One should never forget this.  We cannot act as prosecutor and defendant at the same time and in addition sit on the judge’s bench.  We confront our present thinking with earlier thinking, but we have no possibility of taking a judge’s stand on a point outside.”  (1930 [1983, 46])  It follows that knowledge is an instrument whose efficiency for our purposes can be discerned but not its accuracy in an absolute sense.  
	Frank spoke similarly of “the instrument ‘science’” and added a semiotic rendition of its workings.  “What then are the elements of which the instrument which we call science or cognition is composed?” he asked and answered: “the system of science consists of symbols.” (1929/30 [1949b, 105, italics added])  The advantage gained by this instrument was bought for a price, however.  As he put it, when discussing the working of this instrument two years later in greater detail: “All these relationships between symbols say nothing about real experiences, they are only part of the tool for mastering them.” (1932 [1998, 18])    
	In varying an old injunction—indeed one issued by both Mach and Boltzmann—Frank’s (and Hahn’s and Neurath’s) anti-realism may also be put as:  ‘Do not mistake models for reality.’  What they did was to try and follow through this thought consistently.  All of Hahn, Frank and particularly Neurath, of course, fully participated in the conflations about truth which even Carnap was guilty of around 1932.  
	Neurath is often described as a proponent of the coherence theory of truth.  What prompts such interpretations are statements like “... if a genuine sentence contradicts accepted genuine sentences and is sacrificed, we call it ‘false’; to ask for a further ‘criterion of truth’ makes no sense.  There is no court of appeal outside the totality of sentences.  We do not therefore speak of ‘verification by means of the given’.” (1933 [1987, 6])  Like Carnap in 1932, Neurath seems guilty of a conflation here, allowing no truth to transcend what its criterion (here: coherence) may detect. Yet the ascription of coherence theorist of truth is one which Neurath himself rejected repeatedly (and Carnap for him).  His misleading remarks—like “Statements are only compared with statements”—are better interpreted as desparate attempts to do without correspondence truth.  
	Similar charity is required by his colleagues Frank and Hahn.  Hahn’s claimed: “As against the metaphysical view that truth consists in a agreement with reality—though this agreement cannot be established—we advocate the pragmatic view that the truth of a statement consists in its confirmation.” (1933 [1987, 43])  Frank also appreciated what he called the “pragmatic conception of truth”:

“The physicist in his own scientific activity has never employed any other concept of truth than that of pragmatism.  The ‘agreement of thoughts with their object’, which the school philosophy requires, cannot be established by any concrete experiment. ... In reality, physicists compare only experiences with other experiences.  They test the truth of a theory by what it has become customary to call ‘agreements’.” (1929/30 [1949, 101-2])  

What Hahn and Frank offer would not seem to buy us much, despite the former’s advance on naive veri- and falsification, since one can object that an epistemic conception of truth represents a mistaken conception as much as metaphysical correspondentism.  Frank’s passing assertion that “unambiguity or freedom from contradictions is the most essential attribute of every cognition” (ibid., 102) attracted criticism for its apparent coherentism already from Schlick (as we shall see below) and some of Hahn’s argumentation invites the criticism of undue reliance on verificationism.  What ought to be remembered here, however, is that Hahn’s discussion of truth placed the major emphasis on the “criterion” that was offered by confirmation: “agreement with reality cannot be the criterion of truth” (1933 [1987, 44]).  Likewise Frank stressed that Mach and James had been concerned with the “criteria of truth” (1929/30 [1949, 102]).

3.2	One thing is clear: Hahn, Neurath and Frank wished to discount whatever it was about truth that exceeded possible confirmation.  I want to suggest that, importantly, what mattered to them was not some reduction of truth to confirmation, but rather the re-orientation of our cognitive efforts towards statements that can be confirmed or disconfirmed.  Their instrumentalist anti-realism as much as their operationalist truth-talk were anti-correspondentistically motivated in as much as they tried hard to dislodged the old and seductive image of knowledge as correspondence of thought and true reality.  Viewed in this way, their adoptions of the various versions of veri- and falsificationism were but means that could be happily discarded when a sharper form of delimiting the domain of sensible discourse became available.  (Reduction to some privileged given was not the intended point but instead the control over discourse that was provided by the criterion of intersubjective testability in principle.) 
	Note that such a reading of the intention with which the “pragmatic view” of truth was wielded is compatible with a non-correspondentist conception of Tarski’s theory of truth, since it aims at changing the traditional correspondentist conception of knowledge and truth, not the concept of truth as such.  That is to say, the literally pragmatist, indeed epistemic conception does indeed contradict the “absolute” conception of truth of Tarski, but we may read Hahn, Frank and Neurath as trying to get away from truth altogether and work rather with a notion of reasoned acceptance of knowledge claims.  What has proved so very confusing about this strategy is, of course, that in different ways Neurath and Frank and Hahn believed it advisable — perhaps in order to preserve the continuity of scientific discourse—to put this reorientation forward under the guise of a redefinition of truth; they would have been far better off to declare that they wanted to do without truth as such.
	If this reading—that Hahn, Frank and Neurath primarily rejected correspondence truth—can be accepted, then Hahn, Frank and Neurath can at least in principle be granted the potential to agree with Carnap’s adoption of the semantic conception of truth.  (That Neurath in fact never accepted it is another matter.)  Moreover, their recasting of the concept of scientific knowledge also assumes centre stage again.  According to the “pragmatic view”, such knowledge would be: not a picturing of reality but the possession and conscious employment of in part highly abstract models for mastery of practical problems.
	One possible misunderstanding of this conception should be ruled out right away.  To understand knowledge as possession and conscious employment of in part highly abstract models for the mastery of practical problems need not amount to instrumentalism in the normal sense.  If we can only make gradual distinctions between theoretical and observational claims (as with Carnap and Neurath), then we also do not have the ususal factual contrast class to the merely instrumental, fictionally understood claims of pure theory.  This, of course, is all to the better, since fictionalism strays into metaphysical territory due to its correspondentist understanding of the non-instrumentally interpreted empirical basis.  By contrast, the fallibilism embraced by Neurath, Hahn, Frank and Carnap to some degree instrumentalized the empirical basis itself. 
	In the Circle’s discussion of 5 February 1931, for example, Hahn stated (against Waismann’s Wittgenstein exegesis) that “[t]heory enters into every statement of everyday language” and that “the sentences of everyday language, of which one thinks that they describe the immediate given and that they are immediately verifiable, are vague and cannot bear logical precision. Logical precision is gained only by introducing theories, but the verifiability is lost”.  One week later, he insisted that “[b]etween language and the given there lies an unbridgeable chasm. In no way can it be turned into a congruence.” And he added: “When it comes to descriptions of the phenomenal realm, neither their truth nor their falsity can be affirmed.”  Whatever the precise relation of Hahn’s suggestion may be to Neurath’s (in)famous Ballungen argument, clearly, Hahn rejected the idea that ‘the given’ provided an unproblematically truth-valuable basis for science.

3.3	To begin to see the wider context and overarching intent of the left Vienna Circle’s anti-correspondentism, consider now Frank’s address in the opening session of the yearly gathering of the German associations of physicists and mathematicians in 1929—the very conference at which the Vienna Circle first went public.  There Frank contrasted the “school philosophy” with the “scientific world-conception” which challenged current philosophical theories of knowledge.  “The school philosophy, whether it calls itself realism or idealism, is characterised by the possession of a certain conception of what is called truth, hence also of what can be regarded as the real formulation of a problem [Problemstellung].”  (1930 [1949a, 94-5])  Frank presented the “basic ideas of this doctrine of school philosophy” in the form which Henri Bergson gave them in his introduction to the French edition of James’ Pragmatism.

“Even a philosophy like that of Kant, which assumes that every scientific truth is such only in relation to the human mind, considers the true propositions as given a priori by human experience.  Once this experience, in general, is organised by human thought, the whole work of science consists in breaking through the obstructing husk of facts, in the interior of which the truth is housed like a nut in its shell.”  (Ibid., 95) 

Frank then contrasted what Carnap had shunned as “essence questions” in the Aufbau with the actual procedures of science.  A scientific problem solution was not to be understood as nutcracking in the sense of “bringing about an ‘agreement between thought and object’”.  Scientific problems confront us “only” with “a question of inventing a procedure which, with the help of a skillfully chosen system of symbols, is capable of bringing order into our experiences, thus making it easier for us to control them” (ibid., 98).
	Frank’s, like Neurath’s and Hahn’s rejection of the correspondence theory was epistemologically motivated. What I want to point to particularly, however, is the conception with which Frank opposes it, again in the words of Bergson’s rendering of James:  “We invent truth in order to make reality useful to us, just as we create mechanical devices in order to make the forces of nature useful to us.  It seems to me that one might summarize the essence of the pragmatic conception of truth in a formula of the following kind: Whereas for the other conceptions a new truth is a discovery, for pragmatism it is an invention.” (Ibid.)  What Frank called “pragmatism”, it is evident here, was propelled by a strong constructivist impulse.  One is reminded of his own early radical conventionalism in his (1907), but Frank soon added that for mathematical physicists the pragmatic conception of truth lacked logical precision and “was hard ... to take quite seriously” (ibid., 103).  Clearly, for Frank the “pragmatic conception” of truth and knowledge stood in need of elaboration and further development. 
	That was, of course, the office of the scientific-world conception. Its representatives “not only tried to characterise the system of science in a general and somewhat indefinite way by saying that the system is an instrument to be invented and constructed in order to find one’s way among experiences, but also—and instead—they investigated the structure of this instrument.”  (Ibid., 104)  In particular, they saw it as their task, with the help of “the new logic of Russell and his school ... [to] build up the purely empirical, and hence somewhat vague, conceptions of Mach and James into a real system of the scientific world conception that was superior to the school philosophy from the standpoint of formal logic as well.”  (Ibid.)
To this end Frank then outlined Schlick’s semiotic conception of truth from Allgemeine Erkenntnislehre, divorced from its original realism and married to his own instrumentalism.

“So the concept of agreement, insofar as it is to mean sameness or similarity, melts away before the rays of analysis and what is left of it is only unique coordination [Zuordnung].  In this consists the relation of the true judgement to reality, and all those naive theories according to which our judgements and concepts are able in some way to picture reality are completely demolished. ... The judgement pictures the nature of what is judged as little as a musical note pictures a tone, or the name of man pictures his personality.”  (Quoted in Frank (1929/30 [1949, 105-6]); trans. amended partly to reflect Schlick (1918 [1925 [1985, 61]])

Clearly, this quote suited Frank’s purpose well: the metaphysics of correspondence were what Schlick attacked.  By contrast, Frank noted pointedly about Reichenbach that his “acceptance of the realist standpoint” placed him “closer to school philosophy” (ibid., 112, trans. amended).  Whether Frank was completely correct about his allies is debatable, of course; I will return to this presently.  Note, in any case, that the Aufbau gets top billing in Frank’s narrative of the liberation of philosophy from metaphysics as the “most determined” attempt to provide a Russellian implementation of Machian anti-philosophy.
	So while Hahn and Neurath focussed on what they considered to be the constructive aspect of the denial of correspondence truth, the turn of attention to the notion and process of confirmation, Frank also lingered on the image of truth and knowledge that such a denial was meant to reject.  Putting the two together on the prestigious occasion of the Prague conference was intended to impress on his mostly German fellow professors of physics and mathematics two points.  The first point was that philosophy mattered for science.  Far from being trivial, it is important to see that this charge served to locate a disagreement with his, after all, well-educated audience.  “Nowhere is there a point where the physicist must say: ‘Here ends my task, and from here on it is the task of the philosopher.” (Ibid., 114)  Frank’s all-important second point was that it was not the establishment’s professed philosophy of science that mattered for science.  “The rise of the physics of Galileo and Newton brought about the breakdown of the philosophy of Aristotle, which attempted to show the eternal truth of the physics of antiquity.  Similarly, beside the relativity theory and quantum mechanics there cannot exist a philosophy which constitutes that contains a fossilisation of earlier physical theories.”  (Ibid., 115)  Perhaps not surprisingly, Frank’s plea for the scientific world conception met with no immediate enthusiasm.  He reported that his wife Hanja said to him afterwards: “It was weird to listen.  It seemed to me as if the words fell into the audience like drops into a well so deep that one cannot hear the drops striking the bottom.  Everything seemed to vanish without a trace” (1949a, 40).  
The presumably prior and primary objective was achieved, however: to serve notice of a philosophical and indeed cultural struggle at hand.  In their place and time—the first republics of Germany, Austria and Czechoslovakia—the left Vienna Circle’s battle against metaphysics was a battle to uphold the Enlightenment standards of truth-evaluable public discourse.  Even more concretely, in Prague on 16 September 1929, Frank’s rhetoric portrayed it as a battle for the soul of science, in particular the soul of German science of their day.

4.   	Discussion

A number of critical questions will have occurred to readers.  One issue is doubt whether it is altogether felicitous to call the all-embracing instrumentalism of the left Vienna Circle a form of ‘pragmatism’: does this really do justice either to Peirce’s speculations or to James’ religious sensibilities, say?  Another issue concerns the role of Schlick: doesn’t our criterion make him a member of the left wing of the Circle as well?  And lastly: what does it say about the interpretation of the left Vienna Circle’s attitude towards truth that it remains unclear whether any of its other members followed Carnap’s example of how to make anti-correspondentism respectable?

4.1	Here we must note first that it was Hahn’s and Frank’s own choice of term for the view they championed.  Hahn explicitly referred with quotations not only to Dewey’s Studies in Logical Theory (1903) but also to James’s Pragmatism (1907)—where, incidentally, the French conventionalists, also of great importance to the Vienna Circle, were mentioned amongst the precursors of pragmatism.  Frank notably did not mind borrowing from Henri Bergson in order to characterise both the early pragmatist stages of the opposition and the outlines of his preferred attitude towards truth and knowledge.  Neurath, meanwhile, took a more critical stance towards James (and Schlick’s suggestions to adopt his label “radical empiricism”), but he was immensely pleased to have won over Dewey to contribute to the International Encyclopedia of Unified Science in the late 1930s. 
	Overall, these references suggest that Hahn’s, Frank’s and Neurath’s sympathies primarily extended to the Deweyan type of ‘scientistic pragmatism’, a sober kind of constructivism from which Rorty’s ‘neo-pragmatism’ explicitly seeks to distance itself (for the price of postmodernist allegiances).  Agreement with Peirce was apparently not a concern for them.  Similarly, James was important predominantly for his rejection of the correspondence theory, not his other views; given Hahn’s long-standing Russellian sympathies in other respects, this reference serves to indicate the depth of his anti-correspondentism.  Yet it is also questionable just how much Dewey they had taken on board by the late 1920s.  Sceptics may rightly argue that the de facto convergence between viewpoints championed by members of the left Vienna Circle in the later 1930s and Dewey’s Theory of Inquiry cannot be backdated without further ado.
	There is, however, still an additional dimension to Hahn’s and Frank’s adoption of the label ‘pragmatism’: it too is part of their self-conscious positioning in the academic and cultural politics of their time.  Pragmatism was briefly but widely discussed by German philosophers in the years 1908-10, following the German translation by Jerusalem of James’ Pragmatism, and near-universally dismissed on account of its supposedly shallow and unphilosophical outlook.  Championing preferred views as ‘pragmatist’ was yet another way for Hahn and Frank in which to signal dissent from the Germanic  Sonderweg, the self-styled cultural separatism celebrated by much of the German professoriat at the time, and instead declare their own allegiance to the Western scientific enlightenment tradition.
	Incidentally, just as Frank was ready to champion constructivist ideas under the guise of ‘pragmatism’, so he was not afraid to wear an explicitly ‘positivist’ mantle in promoting them.  (Flying a Machian flag also signalled anti-metaphysical opposition to “school philosophy”.)  His 1929 address repeatedly stressed the Machian provenance of the Vienna Circle’s new approach to the philosophy of science and in his later Kausalgesetz, he made his anti-correspondentist points against Planck as a “positivist” (1932 [1998, 13-14]).  ‘Pragmatism’ and ‘positivism’ were banners, self-consciously flown to mark the Circle’s Frontstellung in the battle against metaphysics—as evident in Frank’s opening address at the yearly congress of German physicists and mathematicians in Prague.

4.2	Another critical issue concerns the proximity of Bergson’s Jamesian pragmatic-epistemic conception of truth and Schlick’s early semiotic conception of truth as unique coordination of symbol to fact.  Whether Frank’s expository liberties were particularly felicitous is another matter; the critical question is whether my interpretation of the left Vienna Circle’s distinction correctly diagnoses their opposition to Schlick.  There is first the question of whether Frank got Schlick right, second what might follow from it.  Would Schlick’s noted opposition to correspondence truth not make him a member of the left Vienna Circle as well?
	First, readers of Schlick’s General Theory of Knowledge will be puzzled by his apparent tolerance of correspondence.  In the very paragraph from chapter 10 quoted above we read: “No other sense remains for the word ‘agreement’ than that of unique coordination or correspondence. We must dismiss from our minds altogether the notion that a judgement can be more than a sign in relationship to a set of facts, that the connection between the two can be anything more intimate than mere correspondence.” (1918/25 [1985, 61])  The explanation is simple.  Comparison with the original makes clear that “or correspondence” must be simply deleted and that the second occurrence of “correspondence” must be replaced by “coordination” (Zuordnung).  The all-important point that coordination is not correspondence is literally lost in the translation.  Luckily, Frank spotted the point in the original.  Yet—rendering the job of the English reader even more difficult—the translation of Frank’s Prague address renders all of Schlick’s “Zuordnungen” in the quote at issue as “correspondence” (1929/30 [1949, 105]).  One is tempted to compensate for this by noting that the by Schlick and Frank much-derided Kantian “agreement [Übereinstimmung] of thought with its objects” might just as well be called the “correspondence of thought with its objects”.
	In both the 1918 and the 1925 editions of his Erkenntnislehre then, Schlick explicitly argued for the semiotic conception against the ‘sameness’ or ‘similarity’ version of the correspondence theory of truth.  What is important for present purposes, however, is whether Schlick held to his opposition to the correspondence theory still in the late 1920s and early 1930s.  At that time Schlick was very strongly influenced by Wittgenstein and his Tractatus, as evident in Schlick’s new concern with the nature of elementary sentences and the requirement of strict verification, etc.  On this count, the Schlick of around 1929 was a dark horse to his fellow Circlists, who would have been hard-pressed to detect his change of view which was becoming clear only gradually.
But the question also arises: does the picture theory of the Tractatus entail a correspondence theory of truth?  The answer would appear to be that it does not entail a correspondence theory in quite the qualitative resemblance sense in which such theories were explicitly rejected in the Erkenntnislehre, but a correspondence theory nonetheless, namely, one that postulated an isomorphism of logical structure between language and the world: 

“What any picture, of whatever form, must have in common with reality in order to be able to depict it—correctly or incorrectly—in any way at all, is logical form, i.e. the form of reality. … 
What a picture represents is its sense.  
The agreement of its sense with reality constitutes its truth or falsity.” (1922, 2.18, 2.221-222)

It was, of course, prominently against Wittgenstein’s picture theory that the left Vienna Circle reacted.  Neurath’s opposition is well-known, but Hahn too remarked that “it is a big mistake to infer the structure of the world from the structure of language” (1930b [1980, 8]).  Their view of Schlick’s acceptance of the picture theory was bound to be the opposite of Schlick’s own.  For them, any correspondence of two types of entities, qualitative or logically structural, was to be rejected.  Their opposition to Schlick on this point from the late 1920s onwards was consistent with their appreciation of the earlier arguments of the Erkenntnislehre.
	Since his own earlier arguments in Erkenntnislehre did not explicitly rule out the type of correspondence theory found in the Tractatus, however, Schlick may have adopted it without considering this a change of mind.  Still later, in his 1934-35 contributions to the protocol sentence debate, Schlick seemed to readmit correspondence for his Konstatierungen even more clearly.  Thus against Neurath he explicitly defended the correspondence theory of truth in the very sense of “the good old phrase ‘agreement with reality’” (1934 [1979, 376]) and reaffirmed that “statements can be compared with facts” (1935 [1979, 400 and 404]).  The result: while Frank and Hahn radicalised their Erkenntnislehre-inspired opposition to the correspondence theory of truth, Schlick instead championed the very form of correspondence theory which his criticism in Erkenntnislehre had not yet thought of.
	The analysis of a closely related incident underlines this conclusion.  Schlick, as noted, objected to Frank’s remarks on truth in his Prague address—“unambiguity [Eindeutigkeit] or freedom from contradictions is the most essential attribute of every cognition”— during the Circle meeting of 5 February 1931: “The positivist does not speak of the ‘invention’ but the ‘discovery’ of truth, like Frank’s ‘school philosophy’.”  Schlick felt that his own conception of truth and the pragmatist one had been approximated much too closely.  In the subsequent brief exchange with Hahn, Waismann took the position that “theories are invented, but not true propositions”, which Schlick corrected to “[n]ot the elementary propositions”.  That was when, by contrast, Hahn himself called into question the role of elementary or atomic statements for science, as noted above (quoted in Stadler (1997 [2001, 246-249])).  This exchange shows not only that the left Circle’s attitude towards truth talk was not shared then by Schlick and Waismann, but also suggests that Schlick did not think that his previous critique of correspondence truth applied to what he took the elementary propositions of the Tractatus to be.  
Lastly, note that Schlick’s charge against Frank was somewhat unfair, for Frank only echoed a central passage from Schlick’s own Erkenntnislehre:  “The one essential virtue of a coordination is its uniqueness [Eindeutigkeit], and since truth is the sole virtue of judgements, then truth must consist in the uniqueness of the designation for which the judgement is to be used.” (1918/25 [1985, 62]).  By early 1931 Schlick conveniently overlooked that his own earlier theory of truth invited now unwanted alliances like that of Frank’s ‘pragmatism’.  Important for us here is that by then Schlick could not have counted as a member of the left Vienna Circle on account of his attitude towards truth.

4.3	Yet what about the notion of the left Vienna Circle itself?  I noted that, given their forceful anti-correspondentism, Hahn, Frank and Neurath could have embraced Carnap’s disquotionalism and thus avoided the debilitating consequences of the failure of verificationism for their anti-metaphysics.  Now Hahn died before the issue arose, yet Neurath clearly did not accept Carnap’s way out.  He continued to suspect the concept of truth of harbouring Aristotelian metaphysics and resolved to do without it.  
	Frank, for his part, did not offend the semanticists quite like Neurath; however, his writings of the 1940s and 50s still display a reliance on what he once called “the pragmatist or operational theory of meaning”: “a doctrine ... is meaningful if we can derive from this doctrine by logical deduction statements which can be tested by our experiences” (1951a, 41).  Coupled with disquotationalism, this stance could, of course, indicate an exemplar-based understanding of the meaning criterion.  The trouble is that Frank refrained from committing himself to disquotationalism and thus clarifying and safeguarding his position.  Instead, he continued to talk only about the “scientific criterion” of truth (1957, 16) and tended use ‘truth’ in quotation marks:  “If a scientific theory is ‘true’, we can derive from it statements that can be checked by observation.” (1951b, 18-9)  So the possibility remains that Frank also did not join Carnap’s rehabilitation of truth.  Does this not mean that he and Neurath (and Hahn) had more in mind with their anti-metaphysics than anti-correspondentism all along?  And if that were the case, wouldn’t this call the entire so-called left Vienna Circle into question?  
We should resist this conclusion for two reasons.  First, as shown above, in the early 1930s, Hahn , Frank and Neurath did share their anti-correspondentism as well as their hapless confusions about truth with Carnap.  Second, Neurath and Frank continued their anti-correspondentism through the later 1930s and into the 1940s, as did Carnap.  So a community of opposition existed throughout.  What the failure to agree explicitly with Carnap’s turn to disquoational truth does show, however, is that the remaining group no longer possessed the theoretical cohesion which it once did.  Indeed, it seems that by the mid-1940s, the left Vienna Circle—like the Vienna Circle proper—no longer existed.  Yet it did exist once and Carnap never retracted the anti-metaphysical animus he shared with the other members of this group.
	In sum, Carnap’s disquotational truth may be taken to represent the positive doctrinal core of the left Circle’s radical version of anti-metaphysics (over and above anti-essentialism).  It was precisely in this sense that Carnap emerged wisened but no less radical when he turned semantic: he never wanted it to effect more than a ban on the metaphysics of correspondence (over and above anti-essentialism).  As is well-known, Carnap had embraced the position rejecting both realism and idealism already in the Aufbau (1928, §§175-178).  Having found himself in agreement with Hahn, Frank and Neurath on this point early on, he took it forward beyond their shared confusions with the conceptual tools offered by Tarski.  As is well-known, in later years, Carnap reaffirmed his anti-metaphysical stance against those who held that the new semantic framework legitimated a return to either to ontology or realism or both, most famously in “Empiricism, Semantics and Ontology” (1950).
	This anti-correspondentist anti-metaphysics, moreover, played a crucial role in the left Vienna Circle’s constructive redefinition of the task of philosophy: not to double-guess science and glean behind the veil of mere appearance, but to devise models for orientation and intelligent action and explore modes of representation and procedures of reasoning that open new fields to systematic thought in science and in life.  It was of course, as noted, this ‘engineering’ approach that constituted the perceived “inner kinship” between the scientific world-conception and what its advocates viewed as the progressive transformative movements of their day.

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