We might begin by asking: Why does “mathematics” merit its own entry here? Should it not be covered in the previous contribution, “Science and Technology”? Mathematics is an integral part of the sciences, and in many respects the role of math and science in literature can usefully be examined together. But mathematics is not a natural science such as physics, chemistry, or biology, which refer to nature and explain phenomena in the physical world by means of observation and empirical evidence. Rather, math is a structural science: It concerns relations between abstract entities, and we do not learn about it from observation, as it is a product of human thought. As such, math has a history of being compared with art: “mathematics, though classified as a science, is equally an art,” Brian Rotman writes in The Routledge Companion to Literature and Science; and sharing characteristics with both the natural sciences and the arts and humanities, math can be seen as a link between these “two cultures.” Attentive to the specificity of math and its relationship to other disciplines, Pynchon’s novels employ it not only as the epitome of reason but also to negotiate the possibilities and limits of art and, particularly, of literary fiction. Against the Day (2006) is the most obviously mathematical novel, but metaphors, concepts, and models from math appear in other works, as well, most significantly in Gravity’s Rainbow (1973) and Mason & Dixon (1997).