Abstract
Ever since Quine, there has been a consensus that the constructions Carnap undertook in the Aufbau do not solve “the external world problem.” This paper seeks to reorient our understanding of the Aufbau not by arguing that Quine was wrong about whether Carnap solved the external world problem but by getting us to reconsider what the external world problem might have been for Carnap. It adduces evidence that one paper that influenced Carnap early on was Karl Gerhards’s 1922 essay “Der mathematische Kern der Aussenweltshypothese.” The paper outlines what Gerhards took the problem of the hypothesis of the external world to be (the unique simplicity or economy of the hypothesis of external objects given the course of experience), the tradition from which it arose (not Hume and Russell but rather Helmholtz and Mach), and how Gerhards attempted to consider this problem in its mathematical core (which becomes a problem of analysis situs and projective geometry). It then relates Gerhards’s project to Carnap’s in the crucial sections of the Aufbau where he projects the qualities of the autophyschological realm on a four-dimensional space-time manifold. Gerhards’s work is brought in not to replace Russell’s in the background to the Aufbau but rather to enrich our sense of the sources Carnap draws from and the problems he there entertains.
An earlier version of this paper was given at the Munich Workshop on Influences on the Aufbau in July 2013. I would like to thank the audience and especially Christian Damböck for both the invitation and for his patience with the revisions. The final version of this paper has been enormously improved by close critical and yet sympathetic comments by Thomas Uebel of an all-too-human penultimate draft.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsNotes
- 1.
A related but somewhat more subtle thesis would be that Carnap achieved his greatness only after divesting himself of such influences, influences now rightly forgotten. Not only do I rather doubt that is how intellectual development works but also I worry that such a methodological claim is inherently conservative in a way detrimental to learning anything substantive from history. After all, it might be that Paul Natorp is in fact a great philosopher but according to the thesis under consideration we already know, because he has been forgotten, that he is not. Philosophical forgetting is not infallible.
- 2.
Some members of the audience in Munich did prefer this vocabulary of impredicative definitions. I think the point is only subtly different in the two ways of speaking: Either Carnap is violating the strictures on definition he gives or he has been vague on the strictures of appropriate definition and is now using a definitional form that might (depending on what we view the philosophical point of the constitutional definitions to be) not discharge the philosophical role it is meant to perform.
- 3.
For more detail see Richardson (1998, Chapter Seven).
- 4.
One of the characteristic features of Carnapian antimetaphysics here can be seen in a philosophical contrast between his work and Gerhards on precisely the psychological setting Gerhards concerns himself with. Gerhards is, that is, concerned to object to Helmholtz ’s notion of “unconscious inference” and to demand a properly scientific, explicit inference in its stead. Carnap is happy to let the psychology be what it may in the realm of “intuitive understanding” and to give the explicit construction in the guise of a “rational reconstruction.” These remarks were prompted by Thomas Uebel , who noted in personal communication that Schlick ’s notes on Helmholtz in the jubilee edition of Helmholtz that Schlick co-edited are directly critical of Helmholtz along Gerhards’s line. Here Schlick seems closer to Gerhards than to Carnap.
- 5.
On the Erlangen meeting see Thiel 1993.
References
Carnap R (1922) Von Chaos zur Wirklichkeit. Unpublished ms. Document RC 081-05-01 in the Rudolf Carnap Collection in the Archives for Scientific Philosophy in the Twentieth Century, Hillman Library, University of Pittsburgh
Carnap R (1923) Über die Aufgabe der Physik und die Anwendung des Grundsatzes der Einfachstheit. Kant-Studien 28:90–107
Carnap R ([1928] 1967) The logical structure of the World. University of California Press, Berkeley/Los Angeles
Carnap R (1963) Intellectual Autobiography. In: Schilpp PA (ed) The Philosophy of Rudolf Carnap. The Open Court: Chicago and LaSalle, IL, pp 3–84
Cassirer E ([1910] 1953) Substance and function. Dover, New York
Gerhards K (1922) Der mathematische Kern der Aussenweltshypothese. Die Naturwissenschaften 17: 423–430 and 18: 446–453
Quine WV (1969) Epistemology naturalized. In: Quine WV (ed) Ontological relativity and other essays. Columbia University Press, New York, pp 69–90
Quine WV ([1953] 1980) Two dogmas of empiricism. In: Quine WV (ed) From a logical point of view, 2nd edn. Harvard University Press, Cambridge, MA, pp 20–46
Richardson A (1998) Carnap’s construction of the world. Cambridge University Press, Cambridge
Thiel C (1993) Carnap und die wissenschaftliche Philosophie auf der Erlanger Tagung 1923. In: Haller R, Stadler F (eds) Wien–Berlin–Prag. Der Aufstieg der wissenschaftlichen Philosophie. Hölder-Pichler-Tempsky, Vienna, pp 175–188
von Helmholtz H (1894) Über den Ursprung der richtigen Deutung unserer Sinneseindrücke. Zeitschrift für Psychologie und Physiologie der Sinnesorgane 7:81–96
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2016 Springer International Publishing Switzerland
About this chapter
Cite this chapter
Richardson, A. (2016). External World Problems: The Logical Construction of the World and the ‘Mathematical Core of the External World Hypothesis’. In: Damböck, C. (eds) Influences on the Aufbau. Vienna Circle Institute Yearbook, vol 18. Springer, Cham. https://doi.org/10.1007/978-3-319-21876-2_1
Download citation
DOI: https://doi.org/10.1007/978-3-319-21876-2_1
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-21875-5
Online ISBN: 978-3-319-21876-2
eBook Packages: Religion and PhilosophyPhilosophy and Religion (R0)