“I shall not need here mention swimming when he is of an age able to learn and has anyone to teach him. ‘Tis that saves many a man’s life: and the Romans thought it so necessary that they ranked it with letters; and it was the common phrase to mark one ill educated and good for nothing that he had neither learned to read nor to swim. Nec literas didicit nec natare.”

Locke, Some Thoughts Concerning Education, 1690

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“We are like fishes swimming in the sea of sense, bounded above by the superior element, but unable to breathe it pure or penetrate it. We get our oxygen from it, however, we touch it incessantly, now in this part, now in that, and every time we touch it, we turn back into the water with our course re-determined and re-energized.”

William James, “The One and the Many,” 1907

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“What does a fish know about the water in which he swims all his life?”

Attributed to Einstein, 1936/1950