The quotation presents fulfilment as the complete exercise of the capacities with which a living being is equipped. In the surrounding passage, White Fang is hunting and fighting, acting according to instincts and physical abilities shaped by his nature and experience. London describes this state as a kind of fulfilment because the animal is fully engaged in the activity for which he appears especially suited.

The idea combines a philosophical question about purpose with a biological view of behaviour. It suggests that life reaches a high point when ability, instinct and action are closely aligned. Within the novel, however, White Fang later adapts to very different circumstances, including human companionship and domestic life. This makes the statement part of a broader exploration of how inherited tendencies interact with environment and experience. The quotation can therefore be read as a reflection on purpose, capacity and adaptation rather than as a simple rule about how life should be lived.

Full quotation

“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 realising his own meaning in the world; he was doing that for which he was made—killing meat and battling to kill it. 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.”