
Source: Galateo: Or, A Treatise on Politeness and Delicacy of Manners, p. 6
1781, p. 479
Life of Samuel Johnson (1791), Vol IV
Source: Galateo: Or, A Treatise on Politeness and Delicacy of Manners, p. 6
Source: How to Become President (1940), Ch. 6 : How not to offend anybody
Franklin himself calls this an "old maxim" when he repeats it at page 48 http://www.ushistory.org/franklin/autobiography/page48.htm of his autobiography.
Franklin's recognition of this effect caused it to be named after him. Wikipedia, Ben Franklin Effect https://en.wikipedia.org/wiki/Ben_Franklin_effect.
Misattributed
Where Is God (2009, Thomas Nelson publishers)
“I am his Highness' dog at Kew;
Pray tell me, sir, whose dog are you?”
"On the Collar of a Dog".
“If you set a high value on liberty, you must set a low value on everything else.”
Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter CIV: On Care of Health and Peace of Mind