Harcum maintains that the proper assumptions about human nature are established by their relative utility in solving existing human problems. In order to facilitate solutions to familiar problems of daily living, the author advocates a definition of the science of psychology that includes the concepts of human freedom and intrinsic dignity. The author emphasizes the importance of the free will concept to behavioral scientists and practitioners as well as to citizens of the general population who, perhaps without realizing it, are forced users of behavioral science. The author's intention is to show that our cherished beliefs in the concepts of freedom and dignity are consistent with scientific principles and thus will become a vital part of a scientifically designed culture.