"Self-realization and self-fulfilment are the sine qua non for human existence."

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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 London