He had learned well the law of club and fang, and he never forewent an advantage or drew back from a foe he had started on the way to Death. He had lessoned from Spitz, and from the chief fighting dogs of the police and mail, and knew there was no middle course. He must master or be mastered; while to show mercy was a weakness. mercy did not exist in the primordial life. It was misunderstood for fear, and such misunderstandings made for death. Kill or be killed, eat or be eaten, was the law; and this mandate, down out of the depths of Time, he obeyed.
Life? Bah! It has no value. Of cheap things it is the cheapest. Everywhere it goes begging. Nature spills it out with a lavish hand. Where there is room for one life, she sows a thousand lives, and it's life eats life till the strongest and most piggish life is left.
Thus it was that in obedience to the law laid down by his mother, and in obedience to the law of that unknown and nameless thing, fear, he kept away from the mouth of the cave.
Deep in the forest a call was sounding, and as often as he heard this call, mysteriously thrilling and luring, he felt compelled to turn his back upon the fire and the beaten earth around it, and to plunge into the forest, and on and on, he knew not where or why; nor did he wonder where or why, the call sounding imperiously, deep in the forest.
Buck did not read the newspapers, or he would have known that trouble was brewing, not alone for himself, but for every tide-water dog, strong of muscle and with warm, long hair, from Puget Sound to San Diego.
Food and fire, protection and companionship, were some of the things he received from the god. In return, he guarded the god's property, defended his body, worked for him, and obeyed him.
He was a killer, a thing that preyed, living on the things that lived, unaided, alone, by virtue of his own strength and prowess, surviving triumphantly in a hostile environment where only the strong survive.
And not only did he learn by experience, but instincts long dead became alive again. The domesticated generations fell from him. In vague ways he remembered back to the youth of the breed, to the time the wild dogs ranged in packs through the primeval forest and killed their meat as they ran it down.