This post in the third in a series on Science, Technology, and Society. The previous post is here, and the next post is here. All posts in the series have previously appeared on the Partially Examined Life group page on Facebook.

“The meaning of a method is the method of its verification.” – Moritz Schlick

“If you cannot predict, you have not explained.” – Carl Hempel

The Vienna Circle (c. 1920 – 1935) was a group of mathematicians, philosophers, and scientists who sought to reconcile philosophy and science by radically redefining the domain of philosophy. This group (only some of whom actually met in Vienna) included Moritz Schlick, Hans and Olga Hahn, Otto Neurath, Rudolf Carnap, Kurt Gödel, Carl Hempel, Friedrich Hayek, A.J. Ayer, W.V.O. Quine, and Robert Neumann. It emerged largely as a response to Einstein’s account of gravity, which was philosophically problematic because it flatly contradicted ideas that had long held the status of immutable and universal truths: namely, Newton’s account of gravity and Euclidean geometry. With respect to the first, it demonstrated that gravity can and does effect objects that have no mass(i.e. light rays). With the second, it demonstrated that Riemann’s account of geometry (long suspect as prima facie absurd) was more descriptive than Euclid’s. In other words, the relationship between science and truth seemed, for the first time since the Enlightenment, problematic.

Contrary to popular belief (then and now) Einstein did not simply expand upon Newton or Euclid – he reversed and contradicted them. If Newtonian gravity and Euclidean geometry were no longer certain, educated people might well (did, and have continued to) wonder if there was any philosophically firm ground to stand on at all.

According to the Logical Positivists, as the Vienna Circle and their heirs have become known, the proper domain of philosophy is logic and language as applied to observation and scientific theory. In order to remain relevant, philosophy would have to give up its pretensions to settle disputes in aesthetics, ethics, and politics. These were mere opinion, while metaphysics and ontology were simply nonsense. The superiority of empiricist to rationalist, idealist, or other kinds of epistemologies, was sufficiently proven by the explanatory success of empiricist science. The age of the system builders was over – philosophers should accept the reduction of their field to an auxiliary discipline of science. If they did, they would be amply rewarded by renewed relevance, as a helper in the greatest intellectual adventure in history – science. Only a scientifically testable proposition could claim any status as truth, or as falsehood. All other propositions were simply cognitively meaningless.

Problems in philosophy were thus reconceptualized as problems in language. Scientific theories are often expressed in philosophically messy or imprecise language, which these philosophers saw it as their objective to clarify. In order for a statement to be philosophically meaningful, they held, it must be verifiable, at least in principle. “Do dolphins have rights?,” or “is a sunset beautiful?” fail this test, and so are no part of philosophy. On the other hand, “Does light bend in response to the presence of a gravity field?” is. Just as Einstein required the help of mathematicians and other physicists in order to formulate his theory of Relativity, he could also benefit from the help of philosophers to clarify his meaning. His statements might therefore be reconstructed in terms of logically necessary deductions from certain sets of observations. Because both the observations and the mathematics were accepted as axiomatically true, there was no possibility of conflict between philosophy and science – only between different interpretations of the theory, which could then be handed back to the scientists in order to help them get along with their work.

How, exactly, to eliminate metaphysics from physics remained another challenge. As David Hume pointed out, we cannot know that the universe behaves in a regular fashion – it is simply useful to suppose that it does. Consider, for instance, a chicken who has learned, from a lifetime of experience, that the farmer always brings food. That chicken might consider it a self-evident truth of the universe that farmers bring food, and it would have no reason to suppose differently. But one day the farmer comes with the axe. Now, if we consider the proposition “copper conducts electricity,” as a property of the universe, how do we know that we do not stand in the same relationship to that copper, as the chicken does to the farmer? Perhaps tomorrow copper will not conduct electricity. What we have, in other words, in the statement “copper conducts electricity” may be considered a metaphysical proposition – an assumption about the ultimate nature of reality, which is not, in principle, testable. What does a logical positivist, who is the sworn enemy of metaphysics, do with this? He cannot logically demonstrate that copper must conduct electricity, but, if he is going to postulate the theory of conductivity as a necessary logical truth, he is going to have to provide some justification. Since this type of justification is not, in principle, capable of derivation from observation, and appeals to rationalism have been disallowed by the Positivists' insistence on the cognitive emptiness of a priori synthetic truths, some other grounds will have to be sought. It seems, in other words, that Metaphysics still looms in the background.

Most of the Vienna Circle philosophers fled Vienna as the Hitler regime became increasingly aggressive. Moritz Schlick, the founder of the group, refused to leave. He was assassinated in 1936 by a former student who had joined the Nazi party.

The legacy of Logical Positivism has been complex and fruitful. On the one hand, the strongest claims of the Vienna Circle have were mostly discarded by the 1960’s as simply too ambitious. As we shall see, Popper, Quine, and Kuhn would have much to say about this. Although the problem of language, logic, and their relation to scientific theory has proven resistant to sustained analysis, the Logical Positivists seem to have been asking the right questions. Continuations or responses to their original lines of inquiry characterize much discussion within Science, Technology, and Society Studies today.

Daniel Halverson is a graduate student studying the history of Science, Technology, and Society in Nineteenth century Germany. He is also a regular contributor to the PEL Facebook page.