The author brings to the clinical analysis Sherrington's concept of "facilitation" which explains important clinical aspects in psychology and visceral neurology. The author intends to explain his clinical observations of pain (one case with causalgia on superior limb and three cases with angina pectoris and coronary sclerosis). In these cases the anesthesia of the stellar ganglion or the sympathetic thoracic ganglionic chain or the use of roentgen-therapy or psychotherapy eliminated the pain that, through the way of "facilitation", had become "dominant", that is appearing even with inadequate stimulus. The modern experimental neurophysiology gives validity to the following therapeutic interpretation: the anesthesia, roentgentherapy or psychotherapy suppressed the reverberating neural circuit with high degree of driving in all or part of its tract, on the afferent path to the cortex or on the efferent path to the coronaries. The author discusses the clinical value of angina pectoris crises showing facts proving that the "illegitimate" crisis (psychogenic) are caused by the stimuation of autonomic afferents to the cortex in any portion of the nervous system (ganglionic, spinal or cortical). The legitimate crises, determining transitory or definite lesions and even death, are explained by the activity of the coronaries parasympathetic effectors. Pain is presented as a phenomenon of "neural engraving" learnt, memorized and automatized, activated by feed-back mechanisms on the autonomic afferents to the cortex or on the efferents, these last ones more dangerous and sometimes lethal. The author discusses the superestimed psychogenesis of the angina pectoris.