McLaughlin, B. (1987). Theories of Second-Language Learning. London: Edward Arnold.

This book provides a judicious evaluation of the major theoretical approaches to second-language learning, examining the role theory plays - including how a theory is arrived at, accepted or rejected - by reviewing and evaluating theories currently in use. A final chapter discusses what it is that a satisfactory theory of second-language learning must explain, at the same time pointing up how current theories are inadequate.