The First Part of the Institutes of the Laws of England, or, A Commentary on Littleton, (London, 1628, ed. F. Hargrave and C. Butler, 19th ed., London, 1832), First Institute.
Institutes of the Laws of England
“He that cheats another is a knave; but he that cheats himself is a fool.”
Sentence-Sermons from Brigham Young University Quarterly quoted in The Latter-Day Saints' Millenial Star, Vol. 70 https://books.google.com/books?id=eItJAAAAYAAJ&pg=PA452&lpg=PA452&dq=He+that+cheats+another+is+a+knave;+but+he+that+cheats+himself+is+a+fool.&source=bl&ots=WBAQiPjQX6&sig=WLEdKN2_kXPXj8jZALKCp2dguaQ&hl=en&sa=X&ved=0ahUKEwjXmNeF_7HMAhUH42MKHdySDgsQ6AEILzAE#v=onepage&q=fool&f=false
“Doubtless the pleasure is as great
Of being cheated as to cheat.”
Canto III, line 1
Source: Hudibras, Part II (1664)
“He who is wicked and held to be good, can cheat because no one imagines he would.”
Chi è reo e buono è tenuto
Può fare il male e non è creduto.
Fourth Day, Second Story
The Decameron (c. 1350)
“The intention of cheating no one lays us open to being cheated ourselves.”
L'intention de ne jamais tromper nous expose à être souvent trompés.
Maxim 118.
Reflections; or Sentences and Moral Maxims (1665–1678)
ZARATHINIUS, A DEFENCE OF THE ARCANE ARTS
The Darkness That Comes Before (2004)
The Ethics of Belief (1877), The Duty of Inquiry
Context: The harm which is done by credulity in a man is not confined to the fostering of a credulous character in others, and consequent support of false beliefs. Habitual want of care about what I believe leads to habitual want of care in others about the truth of what is told to me. Men speak the truth of one another when each reveres the truth in his own mind and in the other's mind; but how shall my friend revere the truth in my mind when I myself am careless about it, when I believe thing because I want to believe them, and because they are comforting and pleasant? Will he not learn to cry, "Peace," to me, when there is no peace? By such a course I shall surround myself with a thick atmosphere of falsehood and fraud, and in that I must live. It may matter little to me, in my cloud-castle of sweet illusions and darling lies; but it matters much to Man that I have made my neighbours ready to deceive. The credulous man is father to the liar and the cheat; he lives in the bosom of this his family, and it is no marvel if he should become even as they are.
