Joseph Bentley

In the previous chapter I argued that Neurath is correctly categorised as an epistemological naturalist, but noted that his naturalism does not always conform to expectations of typical contemporary naturalists. To specify the distinctive aspects of his naturalism, and the distinctive epistemology of science that resulted from it, is the goal of the current chapter. As in the previous chapter, Frank is utilised as an important companion to Neurath’s philosophical approach. Neurath never made any attempt to provide a systematic explanation of his philosophy of science. His writings are disparate and brief, and often the most insightful and intriguing ideas are implied, assumed, or simply stated and moved beyond. It is not always clear that a consistent, cohesive philosophy undergirds Neurath’s work. The purpose of this chapter is to tease out the systematic account of Neurath’s epistemology of science that he never provided himself.

Despite the growth of interest in the project in the late 1980s and early 1990s, naturalized epistemology has existed for a lot longer. Its origins are typically traced to Quine’s “Epistemology Naturalized” in 1969, although Alex Rosenberg argues that Ernest Nagel also made the argument for naturalism in 1956, and again in 1961, albeit within the intellectual space that had been cleared by Quine’s “Two Dogmas”. But an even earlier form of naturalized epistemology had already been developed in the 1930s by the so-called left-wing of the Vienna Circle, most obviously by Otto Neurath. This chapter explains what is meant by epistemological naturalism, and lays the foundations for demonstrating that this label is appropriate for the philosophical project pursued by the left-wing of the Vienna Circle, including Rudolf Carnap.

In the previous two chapters we saw what Neurath’s naturalistic pragmatics of science can do: provide a theory of empirical evidence that ultimately combines the relevant insights of the psychology of perception with the sociology and history of institutionalised collective endeavours with normative directives arrived at in the light of agreed objectives. Let us now turn to Carnap. What contributions might a logician of science be able to make beyond simply analysing the logic of pre-existing scientific theories? Important as that task may be, one must also ask whether Carnap’s logic of science can, in a comparable and complementary way to Neurath’s pragmatics, make a positive contribution towards shaping the future development of scientific practice. The answer, as will be demonstrated, is yes. Carnap’s method of explication allows the logician of science to contribute to the scientific endeavor both and increased awareness of, and consequent deepening, of scientific practice but also the provision of linguistic and logical innovations.

This chapter will provide an account of Neurath’s protocol statements as fully as possible in their own terms. This means taking them in their historical context within the protocol sentence debates, and in relation to Neurath’s broader philosophical project and motivations as explored in the previous chapter. The role of protocol statements in Neurath’s conception of science is central, and yet for the first-time reader, they can appear completely opaque. It is clear Neurath considers them important, but less clear exactly what the import is. Not only does Neurath never provide a comprehensive account of protocol sentences as he understands them, he also never gives a detailed account of their role or position within science generally. His works therefore require more exegesis than other philosophers’. Here, I attempt to provide what Neurath did not; a detailed account of and argument for Neurath’s conception of protocol statements from the ground up.

Amongst contemporary naturalists, under Quine’s influence, it is assumed that the rejection of the analytic/synthetic distinction is necessary for or equivalent to naturalism. Quine brought naturalised epistemology into the philosophical mainstream, and many accounts treat his route to naturalism as not merely a contingent historical one, but a conceptual one. And Quine’s rejection of the analytic/synthetic distinction is famously developed in opposition to Carnap’s defence of analyticity. The engagement between Quine and Carnap, and their numerous and infamous disagreements, have frequently been interpreted as a process of Quine’s naturalism growing out of a rejection of Carnap’s (supposed) reductionism. This framing however obscures that Carnap ought to be understood as a methodological naturalist. Quine’s intellectual pathway to naturalism is not the only one. Moving beyond the common misunderstanding means recognising that the issues of naturalism and the analytic/synthetic distinction are not coextensive, that a specific conception of analyticity is perfectly consistent with epistemological naturalism, and that just such a conception is maintained by Carnap. Really then, this is a debate between two competing versions of naturalism; one allowing for a conventionalised, semantic notion of analyticity, and another that rejects any attempt to divide analytic from synthetic.

A.J Ayer occupies an unusual and unique position in the history of twentieth century philosophy. He remains both famous and infamous. In England particularly, few philosophers are as well known outside academia; perhaps only Russell and Wittgenstein are more familiar to the general public than Ayer. And yet within philosophy, his work and legacy attract nothing like the respect or reverence of those peers. Ayer is well known amongst philosophers, but not so well thought of. Language, Truth and Logic, the book that made his name and defines his legacy, is extraordinarily well known, easily available, and still features on many undergraduate syllabi, but is remembered primarily as a thrillingly brash failure. And as controversial as the content of LTL is its frequent use as the English language bible of Logical Empiricism (at least to scholars of the Vienna Circle).

This text provides an extensive exploration of the relationship between the thought of Otto Neurath and Rudolf Carnap, providing a new argument for the complementarity of their mature philosophies as part of a collaborative metatheory of science. In arguing that both Neurath and Carnap must be interpreted as proponents of epistemological naturalism, and that their naturalisms rest on shared philosophical ground, it is also demonstrated that the boundaries and possibilities for epistemological naturalism are not as restrictive as Quinean orthodoxy has previously suggested. Both building on and challenging the scholarship of the past four decades, this naturalist reading of Carnap also provides a new interpretation of Carnap’s conception of analyticity, allowing for a refutation of the Quinean argument for the incompatibility of naturalism and the analytic/synthetic distinction. In doing so, the relevance and potential importance of their scientific meta-theory for contemporary questions in the philosophy of science is demonstrated. This text appeals to students and researchers working on Logical Empiricism, Quine, the history of analytic philosophy and the history of philosophy of science, as well as proponents of naturalized epistemology.