This chapter examines Cassirer's view on contemporary science. It revisits Cassirer's lesser-known work Determinism and Indeterminism in Modern Physics and argues that it harbors a significantly new stage of his philosophy of physical science. On the one hand, this work presents the quantum formalism as a limiting pole of the Bedeutungsfunktion, the highest mode of symbolic formation according to Cassirer’s “phenomenology of cognition.” Inspired by Paul Dirac, Cassirer understands quantum mechanics as a symbolic calculus for deriving probabilistic predictions of measurement outcomes without regard to underlying wave or particle “images” – or, as an exemplar of abstract symbolic thought. On the other hand, Cassirer recognizes the philosophical significance of the use of group theory in quantum mechanics as advancing a purely structural concept of object in physics. Hence, Ryckman reveals that Cassirer drew epistemological consequences from the symbolic character of contemporary physical theory that retain relevance for philosophy of science today.

INTRODUCTION

From a contemporary vantage point, the conjunction may appear puzzling. What could Carnap - anti-metaphysical logician, student and “legitimate successor” of Frege - possibly have in common with the founder of transcendental phenomenology? Yet, as Michael Dummett has observed, the German philosophy student of 1903 likely regarded Husserl and Frege as mathematician-philosophers remarkably similar in interests and outlook (Dummett, 1993, 26). To be sure, subsequent developments pushed apart the incipient programs of phenomenology and analytic philosophy. Husserl turned to “transcendental subjectivity” in 1905-1907, whereas analytic philosophy around 1930 took a “linguistic turn” precisely to distinguish its methods from those placing cognitive reliance upon intuition or individual subjectivity. Then again, the 1927 publication of Heidegger's Being and Time inexorably changed perceptions of phenomenology as having acquired an expressly “existential” and “ontological” orientation, preempting and obscuring its original Husserlian impulses towards logic and the foundations of mathematics. Epitomizing this history in a memorable metaphor, Dummett notes that the respective influences of Frege, the “grandfather of analytic philosophy,” and Husserl, a patriarch of “continental philosophy,” run through twentieth-century philosophy like the Rhine and Danube, mighty rivers rising close together, briefly running parallel but then diverging to widely separate seas. Extending the metaphor a bit further, Carnap is a central current flowing into one of these seas, while Heidegger is the torrent surging into the other.

INTRODUCTION

Moritz Schlick, Hans Reichenbach, Rudolf Carnap, Philipp Frank, Herbert Feigl, and Carl Hempel all studied physics at university. Relativity theory and quantum theory, the two revolutionary developments of twentieth-century physics, happily coincided with the rise and consolidation of logical empiricism. Yet the designation “philosophy of physics” was little used by the logical empiricists themselves, while, with notable exceptions, they produced little of what is currently understood under that head, viz., detailed investigations into particular aspects or interpretations of physical theories. Certainly, there are important works of Reichenbach's, a few of Schlick's, mostly from his pre-Vienna days, and one or two others, recognizably belonging to philosophy of physics. Nonetheless, it is something of an anachronism to speak of logical empiricism's “philosophy of physics”.

One reason is that logical empiricist orthodoxy allotted but a narrow window to the legitimate practice of “scientific philosophy”. Carnap's 1934 declaration that “we pursue Logical Analysis but no Philosophy” is perhaps characteristic (Carnap 1934a, 28, emphasis in original). Frank, a working physicist, warned that philosophical deliberation continually posed the threat of becoming an “opium for science” (Frank 1932, viii/1998, 11), and that the very meaning of the term “philosophy of natural science” was to be sharply demarcated from all manner of “school philosophy”.

The initial empirical corroboration of the General Theory of Relativity (GTR) was announced to the world at a packed joint meeting of the Royal Society of London and the Royal Astronomical Society on 6 November 1919. Lengthy data analysis of solar eclipse observations, made the previous May by a joint British expedition to Brazil and to an island off the coast of West Africa, confirmed that the GTR-predicted amount of ‘bending’ of light rays in the solar gravitational field had indeed been found. Under a portrait of Isaac Newton, J. J. Thompson, president of the Royal Society, pronounced this ‘the most important result obtained in connection with the theory of gravitation since Newton’s day, and … one of the highest achievements of human thought’ (quoted from Pais 1982: 305). There followed the ‘relativity-rumpus’ (Sommerfeld 1949: 101), a public clamour that, regarding a purely scientific theory without apparent military or technological application, was completely unprecedented, and is, as yet, unmatched. Almost overnight, Albert Einstein, hitherto largely unknown outside the rarefied (and by present standards, miniscule) circle of theoretical physicists, became world famous and a favoured target of anti-Semitism.

A plausible explanation of this astonishing spectacle points to the exhausted state of European culture, eager for diversion after the ravages of four years of world war, political revolution, and an influenza pandemic in which millions perished. Diversion the theory certainly provided, with the novelty of claims made on its behalf and its aura of incomprehensibility. But even among the scientifically literate, there was considerable controversy and misunderstanding concerning the theory’s physical content as well as its philosophical implications.