
“People who have no vices, have very few virtues.”
According to The Inner Life of Abraham Lincoln (1867) by F. B. Carpenter, Lincoln quoted this as having been said to him by a fellow-passenger in a stagecoach. See also "Washington during the War", Macmillan's Magazine 6:24 http://books.google.com/books?id=rB4AAAAAYAAJ&pg=PA24&dq=folks (May 1862)
Posthumous attributions
Variant: It's my experience that folks who have no vices have generally very few virtues.