THE SOCIAL FORCES 91
a purely hypothetical one. There have been recorded in the medical books many cases in which all sense of taste was want- ing, and the temporary loss of appetite is a common occurrence. Some cases have been brought to light in which this state was chronic, and strenuous efforts were made artificially to introduce into the apathetic body sufficient nutritive material to sustain life. But it is obvious that in any but such exceptional cases, situated in the midst of an environment of intelligence and scientific skill, such a condition would speedily result in death, and that without the aid of natural appetite no creature, however intelligent, scientific, or skilled, could persist. A fortiori, no inchoate and undeveloped being could survive under such circum- stances. If any such creatures have by chance been produced they must have immediately perished and left no record of their evanescent career. This alone is adequate to account, on sound, scientific principles, for the existence of the sensation of appe- tite. If, in the infinite number of devices which we may con- ceive Nature to have tried in her effort to discover a protec- tive principle no such quality had been found there could have been no animal world.
It would be easy to carry this reasoning much farther and to show that the principle applies equally to every other form of desire. Indeed, it is the only conceivable explanation of the fundamental phenomenon of feeling of whatever kind. Pleas- ure and pain are simply devices of Nature for the preservation of such organic beings as have no other adequate means, and the existence of a sentient world is its natural result. Desire is that form of remembrance, either original or inherited, of pleas- ureable sensations which prompts the acts necessary to their repetition, and from the manner in which it has originated as a condition to survival, the satisfaction that results is that which maintains life. Pain, though, as it is now easy to see, a funda- mentally different thing, and not in any proper sense the oppo- site of pleasure, had a similar origin, and the class of negative forces last considered result from the device called pain, which all creatures susceptible of it instantly fly from, and thus pre-
