This chapter explores the value of the theory of conceptual blending, originating in cognitive science and linguistics, for understanding the kind of literary creativity involved in major generic inventions, as exemplified by the work of Chrétien de Troyes, Cervantes, and Shakespeare. Conceptual blending describes how, when humans draw upon metaphors, analogues, and paradigms from two or more experiential or cultural domains, they “blend” together aspects of each source domain. They thereby create a newly imagined conceptual space in which new scenarios and mini-narratives test the cogency and elasticity of particular blends and determine whether they may be “run.” Because literary art invites readers to engage not just in simulations of represented content, but also in emulations of the processes by which authors and characters transform content, such art clearly depicts and encourages blending creativity. The chapter suggests that Chrétien draws on Abelard’s theology as well as Latin and Celtic sources as input domains, that Wolfram von Eschenbach’s c. 1210 Parzival does likewise, and that elements of Abelard’s theology congenial to literary innovation are rearticulated by Erasmus, thereby helping to prime the literary creativity of Shakespeare and Cervantes. Cultural memories of diverse established forms and ideas offer possibilities for associative combinations and predictive representations. In the writers most consequential for literary history, these move from “everyday” creativity to daring and innovative blending of genres, styles, and thoughts.