But why say more? All men live enveloped in whale-lines. All are born with halters round their necks; but it is only when caught in the swift, sudden turn of death, that mortals realize the silent, subtle, ever-present perils of life. And if you be a philosopher, though seated in the whale-boat, you would not at heart feel one whit more of terror, than though seated before your evening fire with a poker, and not a harpoon, by your side.
Philosophical/metaphysical leap at the end (as he often provides). He suggests that as mortals we are all constantly subject to danger and death; our domestic safety is an illusion. Just when I was thanking my stars that I never have to encounter whale line in the midst of a hunt, he reminds us that if we open ourselves to the true precariousness of life and limb, we would recognize the ubiquitous risk of life itself. (This reminds me in some ways of Montaigne's "To Philosophize Is to Learn How to Die": through practice they get to a point where they can shrug at such immediate terror as the line.)