This article presents excerpts of the three lectures delivered by George F. Still on March 4, 1902, March 6, 1902, and March 11, 1902. In the first lecture, Still discussed several points in the psychology and development of social control in the normal child and considered the occurrence of defective moral control in in association with general impairment of intellect. Moral control is dependent upon three psychical factors, a cognitive relation to environment, moral consciousness, and volition, which in this connexion might be regarded as inhibitory volition. Moral control, therefore, is not present at birth, but under normal psychical conditions is gradually developed as the child grows older. In his second lecture, Still considered the occurrence of morbid defects of moral control in children without general impairment of intellect and without physical disorder. He pointed out that it is possible to recognise certain groups of cases differing in the time of onset and in the duration of the disorder; that whilst in some cases and defect of moral control dated from the earliest period at which such control becomes possible, in others nothing abnormal was observed until the child was already several years beyond the age of infancy. In his third lecture, Still mentioned a further variety of occurrences of a morbid defect of moral control apart from obvious physical disease and considered more fully some of the grounds upon which these defects are regarded as morbid.