Conceptual blending, also called conceptual integration or view application, is a theory of cognition developed by Gilles Fauconnier and Mark Turner. According to this theory, elements and vital relations from diverse scenarios are "blended" in a subconscious process, which is assumed to be ubiquitous to everyday thought and language.
The development of this theory began in 1993 and a representative early formulation is found in the online article Conceptual Integration and Formal Expression. Turner and Fauconnier cite Arthur Koestler's 1964 book The Act of Creation as an early forerunner of conceptual blending: Koestler had identified a common pattern in creative achievements in the arts, sciences and humor that he had termed "bisociation of matrices." A newer version of blending theory, with somewhat different terminology, was presented in Turner and Fauconnier's 2002 book, The Way We Think. Conceptual blending, in the Fauconnier and Turner formulation, is one of the theoretical tools used in George Lakoff and Rafael Núñez's Where Mathematics Comes From, in which the authors assert that "understanding mathematics requires the mastering of extensive networks of metaphorical blends."
Conceptual blending is closely related to frame-based theories, but goes beyond these primarily in that it is a theory of how to combine frames (or frame-like objects). An early computational model of a process called "view application", which is closely related to conceptual blending (which did not exist at the time), was implemented in the 1980s by Shrager at CMU and PARC, and applied in the domains of causal reasoning about complex devices and scientific reasoning. More recent computational accounts of blending have been developed in areas such as mathematics. Some later models are based upon Structure Mapping, which did not exist at the time of the earlier implementations.
In his book The Literary Mind (p. 93), conceptual blending theorist Mark Turner states that