Page:Popular Science Monthly Volume 52.djvu/457

Rh as the race exists, for general inadequacy would mean extinction of the species.

The intellect, as distinguished from lower mental operations, is the choice among responses to external conditions. Complex conditions permit a variety of responses. Varying conditions demand a change of response. This demand is met by the intellect. The intellect rises with a complex or changing environment. The greater the stress on a race of thinking creatures, the more active and effective their thoughts. The growth of man has been a succession of triumphs over hard conditions. The races which have been successful have arisen from adversity. Prosperity has been the conquest of hard times. Human progress in general has come through the falling away of the ineffective. The "fool-killer" has been its most active agent. "The goodness and the severity of God" are in science one and the same thing, as they were in the thought of the prophet. Its essence is the survival of those who can live and act effectively and happily in the conditions which surround human and animal life. The power of safe and accurate response to external conditions is the essential feature of sanity. The inability to adapt action to need is a character of insanity. Insanity, except as protected by human altruism, means death.

The difference between intellect and instinct in lower animals may be illustrated by the conduct of certain monkeys brought into relation with new experiences. At one time I had two adult monkeys, "Bob" and "Jocko," belonging to the genus Macacus. Neither of these possessed the egg-eating instinct. At the same time I had a baby monkey, "Mono," of the genus Cercopithecus. Mono had never seen an egg, but his inherited impulses bore a direct relation to feeding on eggs, as the heredity of Macacus taught the others how to crack nuts or to peel fruit.

To each of these monkeys I gave an egg, the first that any of them had ever seen.

The baby monkey, Mono, being of an egg-eating race, devoured his eggs by the operation of instinct. On being given the egg for the first time, he cracked it against his upper teeth, making a hole in it, sucked out all the substance, then, holding the eggshell up to the light and seeing that there was no longer anything in it, he threw it away. All this he did mechanically, automatically, and it was just as well done with the first egg he ever saw as with any other he ate. All eggs since offered him he has treated in the same way.

The monkey Bob took the egg for some kind of nut. He broke it against his upper teeth and tried to pull off the shell, when the inside ran out and fell on the ground. He looked at it for a moment in bewilderment, and then took both hands and scooped up the yolk