Our experience that patients with severe schizophrenic symptoms tend to improve whether lobotomized or not confirms the need for control cases in studies of the effects of lobotomy.In series rigorously matched regarding the general and specific severity of symptoms, we find that the lobotomized patients show symptomatic improvement with a frequency reliably greater than that of the controls. They appear more nearly normal. Anxiety is diminished. Resistive isolation and schizophrenic disorganization appear diminished and paranoid projection is diminished.The hypothesis is presented that the splitting of the schizophrenic process is the result of a conflict, unresolvable to the patient, reflected, on the psychological side, by anxious preoccupation and, on the neurological side, by an unresolving morbid resonance or eddy of neural activity between cortex and diencephalon, which jams the higher circuits and leaves the control of behavior to lower centers capable only of stereotyped inflexible and defensive adjustments. Prefrontal lobotomy is presumed to benefit the schizophrenic patient by destroying circuits involved in the maintenance of this morbid eddy or resonance and permitting him more effectively to integrate and use what he has left.