 (1) Although his work deepened the problem of underdetermination by insisting that logic plus data is insufficient to determine theory choice, Kuhn reduced the magnitude of the problem of justifying scientific claims by rejecting traditional realism and the correspondence theory of truth. No longer must scientists justify a theoretical claim as true. Instead, he adopted the Kantian critical position that no enterprise, including science, has the ability to establish the final, metaphysical truth about the world. Instead, science is largely a problem-solving enterprise, and scientists are in position to evaluate the goodness of proposed problem solutions, relative to previous attempts. “[T]he unit of scientific achievement is the solved problem” ([1962] 1970a: 169). What demarcates science from nonscience and pseudoscience is sustained support (over historical time) of a puzzle-solving tradition, not the application of a nonexistent “scientific method” to determine whether the claims are true or false or probable to some degree. With justified truth claims gone, new accounts of scientific discovery, knowledge, explanation, and progress will also be needed.