What is knowledge? How is it acquired? How are claims to knowledge to be validated? Can man achieve rational certainty, or is he doomed to perpetual doubt? How We Know answers these and related questions by providing an uncompromising defense of reason, logic, and objectivity. Using vivid examples, Dr. Binswanger traces the hierarchical development of knowledge, from its base in sensory perception, to conceptformation, to logical inference, to its culmination in the principles of science and philosophy.