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.
Jack LondonThe great task demanded of man is reproduction. He is urged by passion to perform this task. Passion, working through the imagination, produces love. Passion is the impelling factor, imagination the disturbing factor; and the disturbance of passion by imagination produces love.
Jack LondonThey were not half living, or quarter living. They were simply so many bags of bones in which sparks of life fluttered faintly.
Jack London