Mater et Magistra §205

²⁰⁵ The root cause of so much mistrust is the presence of ideological differences between nations, and more especially between their rulers. There are some indeed who go so far as to deny the existence of a moral order which is transcendent, absolute, universal and equally binding upon all. And where the same law of justice is not adhered to by all, men cannot hope to come to open and full agreement on vital issues.