“He had come to know quite thoroughly the world in which he lived. His outlook was bleak and materialistic. The world as he saw it was a fierce and brutal world, a world without warmth, a world in which caresses and affection and the bright sweetness of spirit did not exist.”

“The pitch to which he was aroused was tremendous. All the fighting blood of his breed was up in him and surging through him. This was living., though he did not know it. He was realizing his own meaning in the world; he was doing that for which he was made.... He was justifying his existence, than which life can do no greater; for life achieves its summit when it does to the uttermost that which it was equipped to do.”

“He had opened up for me the world of the real, of which I had known practically nothing and from which I had always shrunk. I had learned to look more closely at life as it was lived, to recognize that there were such things as facts in the world, to emerge from the realm of mind and idea and to place certain values on the concrete and objective phases of existence.”

“But he is not always alone. When the long winter nights come on and the wolves follow their meat into the lower valleys, he may be seen running at the head of the pack through the pale moonlight or glimmering borealis, leaping gigantic above his fellows, his great throat a-bellow as he sings a song of the younger world, which is the song of the pack.”

“It was what should have been a bright summer day, but the smokefrom the burning world filled the sky, through which the sun shonemurkily, a dull and lifeless orb, blood-red and ominous.”

“It was an old song, old as the breed itself - one of the first songs of the younger world in a day when songs were sad. It was invested with the woe of unnumbered generations, this plaint by which Buck was so strangely stirred. When he moaned and sobbed, it was with the pain of living that was of old the pain of his wild fathers, and the fear any mystery of the cold and dark that was to them fear and mystery. And that he should be stirred by it marked the completeness with which he harked back through the ages of fire and roof to the raw beginnings of life in the howling ages.”

“This man had saved his life, which was something; but, further, he was the ideal master. Other men saw to the welfare of their dogs from a sense of duty and business expediency; he saw to the welfare of his as if they were his own children, because he could not help it. And he saw further. He never forgot a kindly greeting or a cheering word, and to sit down for a long talk with them ("gas" he called it) was as much his delight as theirs. He had a way of taking Buck's head roughly between his hands, and resting his own head upon Buck's, of shaking him back and forth, the while calling him ill names that to Buck were love names. Buck knew no greater joy than that rough embrace and the sound of murmured oaths, and at each jerk back and forth it seemed that his heart would be shaken out of his body so great was its ecstasy. And when, released, he sprang to his feet, his mouth laughing, his eyes eloquent, his throat vibrant with unuttered sound, and in that fashion remained without movement, John Thornton would reverently exclaim, "God! you can all but speak!"Buck had a trick of love expression that was akin to hurt. He would often seize Thornton's hand in his mouth and close so fiercely that the flesh bore the impress of his teeth for some time afterward. And as Buck understood the oaths to be love words, so the man understood this feigned bite for a caress.”