I use Swampman to illuminate the role of thought experiments in philosophy of science. Against Millikan and others, I argue that even outlandish thought experiments can shed light on science and scientific kinds, so long as we understand them as illustrations of scientific reasoning , not as examples of scientific kinds . The logic of thought experiments, understood as illustrations, is analogous to the logic of common experimental paradigms in science. So, in reviving Swampman and showing how h