The major contributions to the concept of synthetic function of the ego have been reviewed. We

have attempted to study the differences between the synthetic function and the integrative function. It seems that the transition point in the developmental line of the function occurs at the time of superego formation. A specific disturbance of the synthetic function, 'free aggressiveness', has been illustrated with clinical examples in the literature. A connexion is indicated between what many consider an abstract concept and the clinical observations of psychoanalysis.