While it is generally agreed that Henri Poincaré was the first to expressly articulate a conventionalist position, there is much less agreement as to what exactly his position was. As well as a considerable number of interpretations, Poincaré's work has inspired a broad spectrum of responses, from attempts to substantiate and extend conventionalism, to purported refutations. Some have gone so far as to challenge the characterization of Poincaré as a conventionalist, implying that he misrepresented, if not misunderstood, his own position. Pierre Duhem is widely considered the cofounder of conventionalism. Although his advocacy of conventionalism is less explicit than Poincaré's, his work nonetheless advances the case for conventionalism considerably. The central pillars of Duhem's philosophy of science are a holistic conception of scientific theories, and the ensuing critique of the feasibility of crucial experiments conclusively verifying or refuting individual hypotheses. If, despite the indecisive nature of observation, scientists come to prefer one theory to another, they must be invoking considerations other than mere compatibility with experience. Hence, conventionalism. Nevertheless, The Aim and Structure of Physical Theory, Duhem's major philosophical work, has also been described as an attempted synthesis between conventionalism and realism (McMullin 1990), and even as a treatise against conventionalism (Maiocchi 1990).
Recall the two forms of conventionalism distinguished in chapter 1, the underdetermination of scientific theory by observation and the conventionalist account of necessary truth.