The man who is conscious to himself that he has exactly observed those measures of conduct which experience informs him are generally agreeable, reflects with satisfaction on the propriety of his own behaviour. When he views it in the light in which the impartial spectator would view it, he thoroughly enters into all the motives which influenced it.
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

Context

“We are pleased to think that we have rendered ourselves the natural objects of approbation, though no approbation should ever actually be bestowed upon us: and we are mortified to reflect that we have justly merited the blame of those we live with, though that sentiment should never actually be exerted against us. The man who is conscious to himself that he has exactly observed those measures of conduct which experience informs him are generally agreeable, reflects with satisfaction on the propriety of his own behaviour. When he views it in the light in which the impartial spectator would view it, he thoroughly enters into all the motives which influenced it. He looks back upon every part of it with pleasure and approbation, and though mankind should never be acquainted with what he has done, he regards himself, not so much according to the light in which they actually regard him, as according to that in which they would regard him if they were better informed.” source