Keeping political power in check
My favorite father-in-law (yes, there have been more than one) once told me that if I ever went fishing make sure that I took two ministers with me.
So, I took the bait. “Why is that, Dick?” And he reeled me in, “Because if you take only one, he’ll drink all the beer.”
Besides being just a joke of dubious quality, the more I thought about it the more wisdom I saw in it. It’s easy to succumb to temptation if nobody’s watching, but if there is someone else there, well, people behave a little better.