ABSTRACT
The painfulness of the feelings produced by forces which tend to destroy organic structures, wholly or in part, is of course common to all creatures capable of feeling. We saw it to be inevitable that during evolution there must everywhere be established such connections between external actions and the modes of consciousness they cause, that the injurious ones are accompanied by disagreeable feelings, and the beneficial ones by agreeable feelings. Consequently, pressures or strains which tear or bruise, and heats which burn or scald, are in all cases painful. That pain is relative not to structures only, but to their states as well, is also manifest. The sensibility of an external part depends on its temperature. Activities appropriate to their needs which give pleasures to savages have ceased to be pleasurable to many of the civilized; while the civilized have acquired capacities for other appropriate activities and accompanying pleasures which savages had no capacities for.
