“I have ever deemed it more honorable and profitable, too, to set a good example than to follow a bad one.”

"Give!" (26 March 1944)
Variant translation: People will always follow a good example; be the one to set a good example, then it won't be long before the others follow.
Tales from the Secret Annex

Of Law and Life and Other Things: Papers and Address of Felix Frankfurter (1965).
Other writings

Vice and Virtue, iii
The Note-Books of Samuel Butler (1912), Part II - Elementary Morality

Source: A Thousand & One Epigrams: Selected from the Writings of Elbert Hubbard (1911), p. 18.

Source: The Chronicles of Prydain (1964–1968), Book IV: Taran Wanderer (1967), Chapter 21
Context: “When I was a child I dreamed of adventure, glory, honor in feats of arms. I think now that these things are shadows.”
“If you see them as shadows then you see them for what they are,” Annlaw agreed. “Many have pursued honor, and in the pursuit lost more of it than ever they could gain.”

Letter to Rev. C. B. Tayler ( 8 July 1853) in Ch. 6 : Undergraduate Life At Cambridge October 1850 to January 1854 — ÆT. 19-22, p. 189
The Life of James Clerk Maxwell (1882)
Context: I maintain that all the evil influences that I can trace have been internal and not external, you know what I mean—that I have the capacity of being more wicked than any example that man could set me, and that if I escape, it is only by God's grace helping me to get rid of myself, partially in science, more completely in society, — but not perfectly except by committing myself to God as the instrument of His will, not doubtfully, but in the certain hope that that Will will be plain enough at the proper time. Nevertheless, you see things from the outside directly, and I only by reflexion, so I hope that you will not tell me you have little fault to find with me, without finding that little and communicating it.

(c. 1734) in a successful argument to persuade his father that a medical education was preferred. As quoted by Friedrich Albert Lange, History of Materialism and Critique of its Present Importance Tr. Ernest Chester Thomas (1882) 2nd edition, Vol. 2, p. 55. https://books.google.com/books?id=X4pQAAAAYAAJ&pg=PA55

La gente è più acconcia a credere il male che il bene.
Third Day, Sixth Story
The Decameron (c. 1350)

Life of Marcus Cato
Bartlett's Familiar Quotations, 10th ed. (1919)