Abstract
The conventional interpretation that Duhem condemned outright any type of thought experiment in Mach’s sense should be, at least in large part, rejected. There are some interesting remarks made by Mach and Duhem that suggest a very different reading. In this paper I shall take up and develop these remarks, which lead to the conjecture that Duhem’s criticism was not intended to be a complete rejection of thought experiments but a completion and supplement of Mach’s theory. Duhem, while retaining the core idea of Mach’s theory – according to which thought experiments cannot break free from the ultimate authority of real world experiments –, laid particular emphasis on the perils of thought experiment, which Mach had overlooked or, at least, underestimated.