H. P. Grice's Desideratum of Conversational Clarity: "Be perspicuous [sic]"

clarum: H. P. GRICE’S DESIDERATUM OF CONVERSATIONAL CLARITY. ANSCHAULICHKEIT (GERMAN) ENGLISH clarity, openness to view, visualizability FRENCH caractère intuitif v. INTUITION and ANALOGY, EPISTEMOLOGY, ERSCHEINUNG, PERCEPTION, REPRÉSENTATION, SACHVERHALT, SIGN. Since the 1930s the German term Anschaulichkeit has presented a typical case of untranslatability, to the point that its importance for philosophical reflection on science has only recently been rediscovered. Deriving from the Kantian tradition, the term’s meaning has been radically modified by quantum theory. Although it is not listed in the Kantian lexicon proper (where we find Anschauung and Anschauungsformen), the term does belong to the tradition inspired by Kant that marks all the work done by German mathematicians, physicists, and physiologists of the second half of the nineteenth century. Anschaulichkeit designates what is translated inaccurately in French as the caractère intuitif or in English by the “visualizability” or “clarity” of a physical theory, but in fact it refers to the possibility of giving phenomena and objects a “spatiotemporal representation,” that is, an image in ordinary space and time. With the appearance of quantum theory, this possibility, and this demand, had to be abandoned, whence a drastic change in the use of the term Anschaulichkeit, a change that took place in two stages. First, Niels Bohr abandoned the maintenance, in the atomic physics, of “spatiotemporal representations through which up to this point we have tried to describe natural phenomena” (“Über die Wirkung von Atomen bei Stossen”), introducing instead of Anschaulichkeit the notion of “symbolic analogy” (symbolische Analogie), the only possible approach to objects that cannot be described in spatio-temporal terms. In a second stage the term Anschaulichkeit is taken up again but redefined in a way that emphasizes, on the one hand, the role of experimental procedures in the definition of a theory’s fundamental concepts (W. Heisenberg, “Über den anschaulichen Inhalt”), and on the other hand—elaborating the Helmholtzian idea of Anschaubarkeit (translated in English by “intuitability”), which, applied to mathematics, appears in Helmholtz’s 1878 lecture entitled “Die Tatsachen in der Wahrnehmung” (“Facts of Perception”)—the necessary abstraction that the physicist has to carry out with regard to his usual mental images: “The new system of concepts also gives the intuitive content [der anschauliche Inhalt] of the new theory. We must thus ask of an intuitive theory in this sense only that it be in itself free of contradiction and that it allow us to predict without ambiguity the results of all imaginable experiments in its domain” (Born, Heisenberg, and Jordan, “Zur Quantenmechanik”). In the late 1920s these changes in the meaning of the term Anschaulichkeit had the effect of breaking out of the original Kantian context. The difficulty of translating the term into other languages can thus be easily explained: to understand it, one has to follow the twofold process of the formation and implosion of a vocabulary specifically associated with the history of German philosophy. Catherine Chevalley REFS.: Bohr, Niels. “Über die Wirkung von Atomen bei Stossen.” Zeitschrift für Physik 34 (1925): 142–57, postscriptum. Born, M., W. Heisenberg, and P. Jordan, “Zur Quantenmechanik.” Zeitschrift für Physik 35 (1926): 557–615. Chevalley, Catherine. “Niels Bohr’s Words and Atlantis of Kantianism.” In Niels Bohr and Contemporary Philosophy, edited by J. Faye and H. Folse, 33–57. Dordrecht, Neth.: Kluwer, 1994. Darrigol, Oivier. From c-Numbers to q-Numbers. The Classical Analogy in the History of Quantum Theory. Berkeley: University of California Press, 1992. Heisenberg, Werner. “Über den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik.” Zeitschrift für Physik 43 (1927): 172–98. “The Physical Content of Quantum Kinematics and Mechanics” in Quantum Theory and Measurement, edited by J. A. Wheeler and W. H. Zurek, 62–84. Princeton, NJ: Princeton University Press, 1983. Heisenberg, Werner, and Max Born. “La mécanique des quanta.” In Electrons et photons, 143–81. Paris: Gauthier-Villars, 1928. Helmholtz, Herman von. “The Facts of Perception.” In Selected Writings. Middletown, CT: Wesleyan University Press, 1971. Miller, Arthur. “Visualization Lost and Regained: The Genesis of Quantum Theory in the Period 1913–1927.” In On Aesthetics in Science, edited by J. Wechsler. Cambridge, MA: MIT Press, 1978.