Pavlovian theory of conditioned reflexes and Ukhtomsky's theory of dominanta are considered as the most important biological concepts of the XX century. They have laid the foundation of the modern views of the adaptive and active character of the nervous activity underlying the integral behavior in the environment. Approach to a burning problem of neurophysiological mechanisms of goaldirected behavior is impossible without a comprehensive study of works of both these schools. They have formed not only the methodological basis of modern investigations but opened a new avenue of attack.