"I stood once upon the deck of a ship watching a shoal of porpoises following us and racing round us: every now and then the brown, sleek, shining bodies of the great creatures rose from the blue waves and entered them again with a soft plunge. Our life is like that: we rise for an instant into the light of life, we fall again beneath the waves; but all the while the soul pursues her real track unseen and unsuspected, as the gliding sea-beast cuts the green ocean twilight, or wanders among the rocks and hidden slopes fringed with the branching ribbons, the delicate tangles of spring-fed groves." Benson.