of pains to prompt to acts that should discontinue those pains. Hardly a word more is needed in favor of the postulate that we have here a separate sensory system introduced and developed, at some time since our first or primary sense, for the special function of physical aversion or neural discontinuance. We have yet more to offer on this subject. But we will only remark here that any sense so specialized to avoidance of baneful events, would necessarily become specially 'made up' into the particular characteristics and associated with the peculiar mental experiences coming to us when baneful events occur, and would, therefore, be specially wrought up into our ideas of baneful events, and into our ideas of detriment and of aversion in the abstract. This would be the case although the pain and the pain processes would, of themselves, be as truly beneficial in essential nature as any other sense or bodily function. Indeed, our pains must be essentially beneficial, in order to have been so fundamentally and widely wrought up into our developed organism. Had their general function been detrimental, it would have become eliminated.
The origin of pleasure is not at first so clear. For it we shall have to follow the destiny of our ancestral worm more closely. At the outset we may note that whatever sense it was in terms of which our worm transacted its primary neural functions, this sense would become from the first wrought up into peculiar mental representation of beneficial occurrences. Necessarily so. For one reason: because organization adapted to beneficial occurrences is at first the only organization that is taken up and perpetuated. The more simple a creature is, the more preponderatingly must its possible experiences be beneficial, in order to survive. As the number of its possible experiences increase, the greater may the absolute number of its detrimental experiences be, and the species yet prosper. The more fundamental a function is, the more nearly invariably must it work beneficially. Primary functions must be fundamental functions. We see, then, how any primary sense, which was the mental correspondent of these functions, must be wrought up into special representation of beneficial experiences,
