| As Philip Kitcher observes, it seems that almost everybody agrees that science constitutes the richest and most extensive body of human knowledge. Among philosophers of science, however, there is curiously very little explicit discussion of scientific knowledge. As a result, the question "What is scientific progress?" almost never gets an answer in terms of the accumulation of scientific knowledge, even though this answer seems to be the most natural one. Indeed, this is how scientists themselves--- from Early Modern natural philosophers to contemporary practitioners---conceive of scientific progress. For scientists, scientific progress occurs when there is an accumulation of scientific knowledge. A scientific episode is progressive when, by the end of such a period of scientific change, we know more than we did at the beginning.;I show that this is how scientists conceive of progress by examining some major episodes from the history of the life sciences, such as Harvey's discovery of the circulation of the blood, as well as some key episodes from the history of the Nobel Prize, especially in physiology or medicine. The Nobel Prize is a setting in which scientists reward their peers for what they take to be important contributions to scientific knowledge. Examining this scientific practice of assessing progress reveals that scientists make judgments about progressive discoveries based on epistemic criteria. This practice also reveals that, for scientists, scientific knowledge is not merely theoretical (inferential) knowledge. They also consider progressive the accumulation of empirical (factual), practical, and methodological knowledge.;Given that scientists take progress to consist in the accumulation of scientific knowledge, I argue that naturalists should articulate an account of progress that does justice to this scientific practice. Taking a naturalistic stance on the question of scientific progress, we want an account of progress that meshes with the history of science and the actual practices of scientists. I propose the epistemic account of scientific progress as such an account. The epistemic account simply says that scientific progress consists in the accumulation of scientific knowledge.;Why is it that philosophers of science have largely ignored the epistemic account of progress? I think this has to do with skeptical arguments, particularly against theoretical knowledge, advanced by the likes of Thomas Kuhn and Larry Laudan. I argue that these arguments do not provide compelling reasons for skepticism and pessimism about the accumulation of scientific knowledge. In order to address these skeptical arguments, I propose to (a) focus on individual claims to knowledge, rather than whole theories, as the units of progress, and (b) give up the distinction between 'knowing that' and 'knowing how'. If we take practical and methodological knowledge to be types of scientific knowledge, as scientists do, then there are good reasons to be optimistic, rather than pessimistic, about the growth of scientific knowledge. |
