“Man prefers to believe what he prefers to be true.”

A broad maxim from a narrow observation — sometimes accurate. Man also proffers belief to acquire an advantage, power, justification / rationalization, material increase, image, position, etc. Truth, at law and otherwise is an absolute, no matter one's preferred belief. I think Sir Francis Bacon prefaced the statement well when interjecting the defining word — "prefer". 

Only boys prefer, men believe the actual fact of want is true. Sorry to say Mr Bacon, in this contribution, did not distinguish between boy and man. This is common problem with our social environment