Robert C. Berwick is Professor of Computational Linguistics in the Department of Electrical Engineering and Computer Science and the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology. He is the author of several books and many articles in the area of human language and cognition, including texts on language acquisition, complexity theory and human language, and the biology and evolution of language, and is co-editor, with Massimo Piattelli-Palmarini, of Rich Languages from Poor Inputs (OUP, 2012; paperback 2015). Edward P. Stabler is Professor Emeritus of Linguistics at UCLA and a Senior Principal Research Scientist at Nuance Communications, specializing in mathematical and computational linguistics, learnability theory, and the philosophy of language and logic. He is the author of The Logical Approach to Syntax (MIT Press, 1992), Bare Grammar (with Edward L. Keenan; CSLI, 2003), and An Introduction to Syntactic Analysis and Theory (with Dominique Sportiche and Hilda Koopman; Wiley-Blackwell, 2013).