In the mental-spaces framework developed by Gilles Fauconnier in the mid-1980s, the mind creates multiple cognitive spaces to mediate its understanding of relations and activities in the world, and to engage in creative thought. These 12 original papers extend the mental-spaces framework and demonstrate its utility in solving deep problems in linguistics and discourse theory. Investigating the ties between mental constructs, they analyze a wide range of phenomena, including: analogical counterfactuals; the metaphor system for conceptualizing the self; abstract change expressions in Japanese; mood in Spanish; deictic expressions; copular sentences in Japanese; conditional constructions; and reference in American Sign Language. The research presented in this volume is intended for linguists and cognitive scientists. The contributors are Claudia Brugman, Gilles Fauconnier, George Lakoff, Yo Matsumoto, Errapel Mejias-Bikandi, Laura A. Michaelis, Gisela Redeker, Jo Rubba, Shigeru Sakahara, Jose Sanders, Eve Sweetser, and Karen van Hoek.