Now, that faculty of the intellect which is dominant in man, and which has raised him immeasurably above the animal, and made him man, is the rational intelligence.  If there is any such thing as a law of history or as continuity in evolution, man’s future progress must depend upon his clearer vision and recognition of the perceptions of this faculty.  Through it man perceives beauty, truth, and goodness, and attains knowledge of himself as a person and moral agent, and recognizes his rights and duties.  Of all this the animal is and remains unconscious; indeed he is not yet a moral being and person in any proper sense of the word.

Inasmuch as the rational perception is the dominant faculty in man, it must perceive the lines along which he is to conform.  Truth, right, and duty must be his watchwords.  These are to be the rules and motives of all his actions.  He cannot live for the body, but for something higher, the mind.  This was proven before man appeared on the globe.  He is to be a mental, intelligent being.  But he is not to be governed by appetite or mere prudential considerations.  These are animal, not human motives.  These are not to be disregarded any more than digestion can be safely disregarded by man.  But they are not to be his chief motives.  He must subordinate these to the higher motives furnished by right and duty.  Man is not merely a mental but a moral being.  If he sinks below this plane of life he is not following the path marked out for him in all his past development.  In order to progress, the higher vertebrate had to subordinate everything to mental development.  In order to become man it had to develop the rational intelligence.  In order to become higher man, present man must subordinate everything to moral development.  This is the great law of animal and human development clearly revealed in the sequence of physical and mental functions.

Must man be a religious being also?  This question we must try to answer in a future lecture.

CHAPTER VI

NATURAL SELECTION AND ENVIRONMENT

I have attempted to show that animal development has not been an aimless drifting.  Functions developed and organs arose and were perfected in a certain order.  First the purely vegetative organs appeared, and the animal lived for digestion and reproduction; then came muscle and it brought with it nerve.  But these were not enough; the brain had all the time been gradually improving, and now it becomes the dominant function to which all others are subordinated.  The experiment was fairly tried.  Mere digestion and reproduction are carried to about the highest perfection which can be expected of them in worms and mollusks.  The bird tried what could be done with digestion ministering to locomotion guided by the very keenest sense-organs and controlled by no mean brain.  Even this experiment was not a success.  But one organ remained, the brain, and on its mental possibilities depend the future of the animal kingdom.  Vegetative organs and muscle have been tried and found wanting.[1]