"The truly moral deterrent from murder, is not constituted by a representation of hanging as a consequence, or by a representation of tortures in hell as a consequence, or by a representation of the horror and hatred excited in fellow-men; but by a representation of the _necessary natural results_--the infliction of death agony on the victim, the destruction of all his possibilities of happiness, the entailed sufferings to his belongings" (Spencer, _Ibid._, p. 120). The external constraints thus serve as a schoolmaster to bring the race and the individual to internal restraint. Gradually the abstract sense of coerciveness, authoritativeness, the need of controlling the present by the future good is disentangled, and there arises the sense of duty in general. But even this "is transitory and will diminish as fast as moralization increases" (_Ibid._, p. 127). Persistence in performance of a duty makes it a pleasure; an habitually exercised obligation is naturally agreeable. In the present state of evolutionary development, obligation, or the demands made by the external environment, and spontaneous inclination, or the demand of the organism, cannot coincide. But at the goal of evolution, the organism and environment will be in perfect adjustment. Actions congenial to the former and appropriate to the latter will completely coincide. "In their proper times and places, and proportions, the moral sentiments will guide men just as spontaneously and adequately as now do the sensations" (_Ibid._, p. 129).