Charles Darwin is generally credited with having formulated the first systematic attempt to explain the evolutionary origins and function of the expression of emotions in animals and humans. His ingenious theory, however, was burdened with popular misconceptions about human phylogenetic heritage and bore the philosophical and theoretical deficiencies of the brain science of his era that his successors strove to overcome. In their attempts to rectify Darwin’s errors, William James, James Mark Baldwin and John Dewey each made important contributions to a theory of emotion, which attempted to put it on a more secure philosophical and scientific footing. My contention is that Dewey and his collaborator, infant experimentalist Myrtle McGraw, succeeded where their contemporaries failed. They pointed the way out of the morass of recapitulationism, and showed how a developmental theory of consciousness, mind and emotion could be formulated that avoided the epistemological and ontological pitfalls of Darwin’s theory. Drawing on an extensive body of research from contemporary experimental studies of infant development, this essay attempts to put the questions raised by these historical figures about the structure, function and value of emotions in a theoretical framework. A developmental theory is proposed about the complex, interacting neurobiological and neurobehavioral factors that contribute to human emotional development. This theory identifies the possible relationships among emotions, consciousness and mind and how their co-development influences the capacity of young children to form moral judgments.