A. W. Carus

In Carnap’s autobiography, he tells the story how one night in January 1931, “the whole theory of language structure” in all its ramifications “came to [him] like a vision”. The shorthand manuscript he produced immediately thereafter, he says, “was the first version” of Logical Syntax of Language. This document, which has never been examined since Carnap’s death, turns out not to resemble Logical Syntax at all, at least on the surface. Wherein, then, did the momentous insight of 21 January 1931 consist? We seek to answer this question by placing Carnap’s shorthand manuscript in the context of his previous efforts to accommodate scientific theories and metalinguistic claims within Wittgenstein’s Tractatus theory of meaning. The breakthrough of January 1931 consists, from this viewpoint, in the rejection of the Tractatus theory in favor of the meta-mathematical perspective of Hilbert, Gödel, and Tarski. This was not yet the standpoint of the published Logical Syntax, as we show, but led naturally to the “principle of tolerance” and thus to Carnap’s mature philosophy, in which the inconsistencies between this first view and the principle of tolerance, which survived into the published Syntax, were overcome.

In 1929 Carnap gave a paper in Prague on Investigations in General Axiomatics; a briefsummary was published soon after. Its subject lookssomething like early model theory, and the mainresult, called the Gabelbarkeitssatz, appears toclaim that a consistent set of axioms is complete justif it is categorical. This of course casts doubt onthe entire project. Though there is no furthermention of this theorem in Carnap''s publishedwritings, his Nachlass includes a largetypescript on the subject, Investigations inGeneral Axiomatics. We examine this work here,showing that it provides important insights intoCarnap''s development during this critical period, thetransition from Aufbau to Syntax,especially regarding the nature and motivation ofCarnap''s logicism. Moreover, we show how theAxiomatics influenced Carnap''s student Gödel inreaching the fundamental logical results that soonafterwards undermined Carnap''s project.

Rudolf Carnap is widely regarded as one of the most important philosophers of the twentieth century. Born in Germany and later a US citizen, he was a founder of the philosophical movement known as Logical Empiricism. He was strongly influenced by a number of different philosophical traditions, and also by the German Youth Movement, the First World War, and radical socialism. This book places his central ideas in a broad cultural, political and intellectual context, showing how he synthesised many different currents of thought to achieve a philosophical perspective that remains strikingly relevant in the twenty-first century. Its rich account of a philosopher's response to his times will appeal to all who are interested in the development of philosophy in the twentieth century.

One thing we have found out about logical empiricism, now that people are examining it more closely again, is that it was more a framework for a number of related views than a single doctrine. The pluralism of different approaches among various adherents to the Vienna and Berlin groups has been much emphasized. Some have gone so far as to suggest that the kind of speculative philosophy now often called "continental" (including, say, phenomenology) can be seen as falling within the framework of views shared by the Vienna Circle. Much is made of Felix Kaufmann's membership in the Vienna Circle, for instance, or of its "Austrian" roots in the phenomenology of Brentano.

Huw Price has sketched a program for a globalized expressivism in support of which he has repeatedly invoked Rudolf Carnap. This paper argues that this is entirely appropriate, as Carnap had something quite similar in mind. However, it also argues that Price’s recent attempts to integrate Robert Brandom’s inferentialism to this program are less successful, and that a more empirically-oriented descriptive pragmatics along Carnapian lines would be a better fit with his original program than Brandom’s explicitly hermeneutical agenda.

Carnap is still often portrayed as a “representationalist.” While the genealogy of this prejudice may not actually go back to Neurath’s response to Carnap’s embrace of Tarskian semantics, there is a continuity of motivation and rhetoric. However, based on a reading of the later Neurath-Carnap correspondence reproduced in this volume, it would appear that the apparent dispute between them over semantics really was largely terminological, with certain differences of emphasis amplified by personality differences and the long interruption of personal contact due to the war. Their conceptions of a language of science can be reconciled. Carnap was neither a representationalist nor an anti-representationalist nor an inferentialist, since ultimately to embrace one of these positions is to endorse an “order of explanation” or ontological primacy, and Carnap rejected ontology.

The revival of interest in Carnap’s philosophy over the past two decades has shed much light on particular aspects of his intellectual development and its context. We now have a better appreciation of the background and motivation of the Aufbau. 1 The radical nature of the Syntax program has fmally, more than half a century after its first publication, begun to be acknowledged.2 And the later Carnap has also been re-assessed; the previously widespread impression that Quine was “right” and Carnap “wrong” in the analytic-synthetic debate has yielded to a more balanced view3, and the broad outlines of Camap’s late philosophy have begun to emerge.

This issue of The Monist on Carnap’s metaphilosophy is another clear demonstration that Carnap’s career, nearly half a century after his death, is far from over. The scope of Carnap studies continues to broaden into new fields, incorporating more aspects of his thought and bringing it to bear on more aspects of philosophy. And more of his previously unpublished and unknown writings continue to appear; this is the third special issue of a journal in the past year or so that includes hitherto unpublished texts by Carnap himself.1 I am also pleased that this issue of The Monist extends from the very early Carnap to the very late Carnap.2The call for papers was partly inspired by the recent burst of interest in metametaphysics, which in its present form3 derives from the debate between Carnap and Quine about ontology during the 1950s. While the Carnap-Quine debate itself is well represented here in the papers by Geoffrey Hellman and Sean Morris, the metametaphysical discussion about that debate is itself largely absent, to my surprise. That was not the intent, though Carnap himself would presumably have been pleased. He would also have been grateful for Thomas Uebel’s paper explaining that his apparent “elimination” of epistemology during the 1930s did not mean that epistemological questions had been ruled out, only that they had been largely turned into practical questions rather than cognitive ones—but practical questions whose answers needed to be informed by a lot of empirical knowledge. Along similar lines, my own paper tries to make clear, using Huw Price’s “global expressivism” as an example and starting point, what a Carnapian “descriptive pragmatics” would actually involve. In his reply, Price acknowledges Carnap as a fellow traveler and leaves room for descriptive pragmatics but also sketches some limits to this endorsement.

Die frühesten Zeugnisse zu Carnaps philosophischer Entwicklung bekunden einen klaren und bewußten Nonkognitivismus, wie vor allem an einem Vortrag aus dem Jahre 1911 gezeigt wird. Wie man weiß, bekannte sich Carnap nach etwa 1929 auch zum Nonkognitivismus, dem er 1963 als erster sogar diesen Namen gab. Zwei Dokumente werden aber manchmal als Gegenbeispiele angeführt, ein nichtveröffentlichter Aufsatz über „Deutschlands Niederlage“ aus dem Jahre 1918, und der skizzenhafte § 152 des Aufbau; es fragt sich also, ob es eine Episode zwischen seinen philosophischen Anfängen und 1929 gab, in der Carnap seinen Nonkognitivismus zeitweise aufgab. Diese Frage wird anhand einer Interpretation dieser zwei Texte verneint. Es wird angedeutet, dass Carnaps Nonkognitivismus von Anfang an sich relativ geradlinig zu einem „Funktionalismus“ im weitesten Sinn entwickelte, in Richtung auf einen „globalen Funktionalismus“ wie ihn heute Huw Price vertritt.