The Knowledge Problem in Mature Science
In the course of the nineteenth century, physical scientists became increasingly self-conscious of the need for a theory of how scientific knowledge was produced. Though many theories were proposed, none won a consensus. As explicitly stated by William Whewell, the core problem was the same for everyone: how to ground claims of knowledge of experience in a way that also justified claiming that the object of these claims was a reality independent of experience that caused experience. Everyone was acutely aware of the Fallacy of Affirming the Consequent and of the logical gulf between induction and deduction. John Herschel, Whewell, John Stuart Mill, August Comte, Hermann Helmholtz, Pierre Duhem, and Ernst Mach were some who proposed theories of science. Of these, Mach alone decisively rejected reality as the objective of science. Meanwhile, the nonscientist J. B. Stallo argued for the fundamental role played by metaphysical concepts in modern science.