Attributed to Aristotle in Diogenes Laertius "The Lives and Opinions of Eminent Philosophers" translated by C. D. Yonge and Henry G. Bohn (p. 188), 1853.
Mark Twain (2017). “The Complete Works of Mark Twain (Illustrated Edition): Novels, Short Stories, Memoir, Travel Books, Letters, Biography, Articles & Speeches: The Adventures of Tom Sawyer & Huckleberry Finn, Life on the Mississippi, Yankee in King Arthur's Court…”, p.8291, e-artnow