This comprehensive, scholarly text offers extensive biographical detail and full coverage of psychology’s pre-19th century philosophical and scientific roots. The authors make connections between recent developments in psychometrics and biological, social, and cognitive psychology and their historical roots through current articles and references. This critical-thinking approach, combined with groundbreaking pedagogy, makes the text interesting and accessible to students and helps them understand the thinking processes that led to major psychological discoveries, as well as how they relate to contemporary specialty areas.