In this chapter, the historical and conceptual connections between Lewis and Kuhn are explored carefully and systematically. There is textual evidence that Kuhn was both directly and indirectly influenced by Lewis. Further parallels show that Lewis is committed to relativism about knowledge, but not about truth, as Kuhn was. Finally, it is argued that Lewis's talk of "the given element in experience" would not be a problem for Kuhn, since the given only has an epistemic role insofar as it is conceptually interpreted, and interpretations are conceptually relative. Thus Lewis helps explicate the epistemological framework for Kuhn, whereas Kuhn shows the concrete implications of a Lewisian epistemology.