“There was nothing the matter with them except they were dead tired. It was not the dead-tiredness that comes through brief and excessive effort, from which recovery is a matter of hours; but it was the dead-tiredness that comes through the slow and prolonged strength drainage of months of toil.”

“In this manner had fought forgotten ancestors. They quickened the old life within him, the old tricks which they had stamped into the heredity of the breed were his tricks... And when, on the still cold nights, he pointed his nose at a star and howled long and wolflike, it was his ancestors, dead and dust, pointing nose at star and howling down through the centuries and through him.”

“...men, groping in the Arctic darkness, had found a yellow metal, and because steamship and transportation companies were booming the find, thousands of men were rushing into the Northland. These men wanted dogs, and the dogs they wanted were heavy dogs, with strong muscles by which to toil, and furry coats to protect them from the frost.”

“There is an ecstasy that marks the summit of life, and beyond which life cannot rise. And such is the paradox of living, this ecstasy comes when one is most alive, and it comes as a complete forgetfulness that one is alive. This ecstasy, this forgetfulness of living, comes to the artist, caught up and out of himself in a sheet of flame; it comes to the soldier, war-mad in a stricken field and refusing quarter; and it came to Buck, leading the pack, sounding the old wolf-cry, straining after the food that was alive and that fled swiftly before him through the moonlight.”

“But, – and there it is, – we want to live and move, though we have no reason to, because it happens that it is the nature of life to live and move, to want to live and move. If it were not for this, life would be dead. It is because of this life that is in you that you dream of your immortality.”

“They alone moved through the vast inertness. They alone were alive, and they sought for other things that were alive in order that they might devour them and continue to live.”

“To have a full stomach, to daze lazily in the sunshine--such things were remuneration in full for his adors and toils, while his ardors and toils were in themselves self-remunerative. They were expressions of life, and life is always happy when it is expressing itself.”