We are mortified when we happen to deceive other people, though unintentionally, and from having been ourselves deceived.
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

add
Author Adam Smith
Source The Theory of Moral Sentiments
Topic deceiving
Date 1759
Language English
Reference
Note
Weblink https://en.wikisource.org/wiki/The_Theory_of_Moral_Sentiments

Context

“and, as in the most cautious the disposition to believe is apt to prevail over that to doubt and distrust; so in those who are the most regardless of truth, the natural disposition to tell it prevails upon most occasions over that to deceive, or in any respect to alter or disguise it. We are mortified when we happen to deceive other people, though unintentionally, and from having been ourselves deceived. Though this involuntary falsehood may frequently be no mark of any want of veracity, of any want of the most perfect love of truth, it is always in some degree a mark of want of judgment, of want of memory, of improper credulity, of some degree of precipitancy and rashness.” source