Bird’s new book, Knowing Science, provides an exemplar of how to do epistemology and philosophy of science together. While I wholeheartedly appreciate his attempt to bridge the gap between epistemology and philosophy of science and find his project promising, I am not convinced by the central thesis of the book that knowledge plays a central role in science. In this article, I focus on Bird’s epistemic account of scientific progress, which is the view that the nature of scientific progress is the accumulation of scientific knowledge. Contra Bird, I argue that scientific progress cannot be fully characterised as the accumulation of scientific knowledge