Rationalization, in many words

"Let it be clear, my boy," Rebaudengo explained, all formality now gone. "What I produce are not forgeries but new copies of genuine documents that have been lost or, by simple oversight, have never been produced, and that could and should have been produced. It would be forgery if I were to draw up a certificate of baptism from which it appeared - forgive the example - that you were a son of a prostitute, born near Odalengo Piccolo," and he chuckled with amusement at such a shameful idea. 

"I would never dream of committing such a crime because I am an honorable man. But if you had an enemy, so to speak, who sought to get hold of your inheritance, and you knew he was definitely not the child of your mother or your father but of a whore from Odalengo Piccolo, and that he had conveniently lost his certificate of baptism in order to obtain your inheritance, and if you were to ask me to produce that missing certificate in order to confound that rogue, I would assist, so to speak, the truth by proving what we know to be true, and I would have no remorse."

From The Prague Cemetery by Umberto Eco