Clinical evidence suggests that asthma and other forms of respiratory anxiety may be precipitated by nascent aggressive feelings involving anal, urethral, or sexual excretory impulses. Stimulation of the excretory mucous membranes by these fantasies sensitizes the respiratory mucous membrane, just as physical stimulation of the excretory membranes stimulates respiration. The nascent excretory aggression arouses fears of excretory aggression from the outside world. The persons whom the patient has felt to be 'good' he now expects to be 'bad' and to attack his respiratory apparatus in a talion manner, which responds physiologically as though it were really attacked by noxious substances.