Meaning of “A ship should not ride on a single…”

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.

Act 5, Scene 2.

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.

The Rape of the Lock, Canto V, lines 29–30 in Pope’s 1717 revision; spoken by Clarissa. Her speech was added in 1717, so the inherited 1714 source year is corrected to 1717. Clarissa’s counsel is immediately followed by the poem’s return to comic battle, preserving the satirical frame.