Despite several decades of empirical research that has supported the utility of cognitive research and therapy, behaviorists continue to battle with cognitivists on epistemological grounds. Therefore, I seek to resolve this battle by reviewing epistemological lessons learned from two other disciplines, Physics and Pragmatism. Paradigm shifts in Physics taught us that formal models of phenomena and causality have just as valuable a role in a science of human behavior as models based on efficient cause and direct observation. Cognitive models have proven their worth as formal models of psychology. Pragmatism has taught us that accountability - to the researcher and theorist, to the clinical professional, and to the consumer of care - needs to be a renewed value in evaluating psychological models. Carefully controlled empirical research has shown cognitive models to have ably met these goals. Therefore, cognition meets epistemological criteria, other than those touted by behaviorists, which commend it as an important model for human psychology.