
“The measure of a man's real character is what he would do if he knew he would never be found out.”
citation needed
The earliest quotations of this give it as anonymous or unknown author. https://books.google.com/books?id=hPIsAAAAYAAJ&pg=PA321&dq=%22what+he+would+do+if+he+knew+it+would+never+be+found+out%22&hl=en&sa=X&ved=0CBwQ6AEwAGoVChMIlvi0prz_xwIVTwaSCh0hVwX5#v=onepage&q=%22what%20he%20would%20do%20if%20he%20knew%20it%20would%20never%20be%20found%20out%22&f=false https://books.google.com/books?id=i2MPAQAAIAAJ&pg=PA16-IA71&dq=%22what+he+would+do+if+he+knew+it+would+never+be+found+out%22&hl=en&sa=X&ved=0CB0Q6AEwAGoVChMIkMmp8rz_xwIV1BGSCh25lAO0#v=onepage&q=%22what%20he%20would%20do%20if%20he%20knew%20it%20would%20never%20be%20found%20out%22&f=false
Attributed