Meaning of “All human wisdom is summed up in these…”

As You Like It, Act II, Scene 1, Duke Senior; 1919 Yale Shakespeare edition edited by Jack R. Crawford, printed page 24 / Wikisource scan leaf 36. “Sweet are the uses of adversity” occurs in Duke Senior’s Forest of Arden reflection on exile, winter and the lessons he claims to find outside court life. It remains fictional dramatic speech rather than Shakespeare’s autobiographical advice or a modern psychological claim about hardship.

Self-Help, Chapter XI, “Self-Culture—Facilities and Difficulties,” Project Gutenberg #935. The passage follows Charles James Fox’s contrast between early success and perseverance after failure, then leads into examples of discoveries and learning produced through mistakes and failed attempts.

Meditations, Book VII, section 61, George Long translation; the full sentence emphasizes readiness for sudden and unexpected onsets.

Rasselas, Chapter XVI; spoken by Imlac while comparing European life with the travelers’ expectations of happiness.

Self-Control, Its Kingship and Majesty, Chapter XIV, “Failure as a Success,” Project Gutenberg #51469. “Failure is often the turning-point...” follows Jordan’s account of a failed log-rafting experiment that nevertheless generated useful hydrographic observations. The word “often” is retained: this is conduct-of-life rhetoric about possible redirection after failure, not a guarantee that failure produces improvement.

Moral printed after “The Hare and the Tortoise” in George Fyler Townsend’s translation of Aesop’s fables.