Meaning of “A moment's insight is sometimes worth a life's…”

Moral printed after “The Lion, the Fox, and the Ass”; the fox changes his conduct after observing the ass’s fate.

As You Like It, Act V, Scene 1, Touchstone; 1919 Yale Shakespeare edition edited by Jack R. Crawford, printed page 89 / Wikisource scan leaf 101. Touchstone says, “The fool doth think he is wise, but the wise man knows himself to be a fool,” while verbally outmaneuvering William in a comic exchange over Audrey. The maxim remains fictional comic dialogue rather than a direct Shakespearean self-help proposition.

Aristotle, Metaphysics, Book I, Chapter I, W. D. Ross translation (1908), validated Wikisource scan leaf 21. 'All men by nature desire to know' opens the work before the discussion of sensation, memory, experience, art and knowledge. This remains ancient philosophy mediated by translation, not a modern empirical finding about cognition.

The Vanity of Human Wishes (1749), first-edition scholar passage, Wikisource scan leaf 28. “And pause awhile from Learning to be wise” turns from the ambitious student’s pursuit of knowledge toward Johnson’s satirical warning that learning does not by itself remove grief, danger or error. This is eighteenth-century moral-satirical poetry after Juvenal, not a modern educational rule.

The Will to Believe, essay “The Will to Believe”; Project Gutenberg #26659. James immediately argues that truth-seeking and error-avoidance are distinct laws rather than two phrasings of one command.

Leaves of Grass (1855), untitled first-edition poem later known as “Song of Myself,” printed page 14 (Wikisource scan page 20). The sentence follows Whitman’s warning against taking things at second or third hand and against looking only through another person’s eyes; the reviewed locator is edition-specific.