Innovative conceptions of the soul flourished in the past century. Worcester and McComb discussed the subconscious as the soul, that unknown aspect of ourselves. The subconscious was the source of religious experience. Myers’ “subliminal self” produced automata that upsurged across the threshold of consciousness; while automata could be pathological, they could also be indicative of the future evolution of the personality. James speculated about souls beyond the individual, even of the earth itself. Jung articulated an understanding of the soul and of psychical reality. Holt recognized soul in the form of consciousness as the “cross-section.” Holt recognized form in “the wish,” as organizing consciousness and behavior. These innovations represented a shift in emphasis from the figural of mental life—consciousness—to its ground. They shifted the conversation about the soul from it being an efficient cause of mental life to it being the formal cause of mental life.

Behavioral psychology was immediately preceded by the reflexology of Russian physiology and the associationism of Thorndike. Physiological reflexology received a sound foundation with the works of Sechenov and Bekhterev, but it was Pavlov who proposed a comprehensive theory of conditioning. Watson’s behavioral formulation defined stimulus and response elements as the substitute to rid psychology of residual mentalistic constructs. Watson’s contemporaries, Holt, Weiss, Hunter, and Lashley, soon restored to behaviorism critical psychological activities. The logical positivist movement expressed an operational spirit and insured the initial success of the behaviorist model. Behavioral psychology expanded beyond the original formulations of Pavlov and Watson. Contemporary reflexology in Russia and in nearby countries expanded to include a wide range of psychological and physiological problems, led by such eminent scientists as Vygotsky, Luria, Konorski, Asratyan, and Beritashvili. In the United States, behaviorism moved through several intellectual stages, through the contributions of Guthrie, Tolman, Hull, and Skinner. A major application of behaviorism was the behavior modification model in clinical settings. Contemporary behaviorism remains a dominant but diffused force in psychology.