The author reviews a large number of 'exceptional states', ranging from trivial everyday lapses to severe pathological conditions. He endeavours to show that nothing is gained by the assumption of a dissociation or splitting of the personality, and himself considers these conditions in the light of the general lability characteristic of all affective mental life. Though interesting in certain respects, the explanations offered would seem to be too general in nature, and—in their present state—to take too little regard of specific mechanisms to be of much assistance.