Always deal with upstanding people. You can put them under an obligation and be under one with them. Their very rectitude is the best guarantee of their behaviour, even in disagreements, the they act as the people they are. Better to fight with honest people than to triumph over bad ones. There is no honest dealing with the dishonest since they feel no obligation to integrity. This is why there is no true friendship among such people, nor is their courtesy genuine, although it may seem so, because it’s not rooted in honour. Shun entirely someone without honour, for the person who doesn’t value honour, doesn’t value virtue. And honour is the throne of integrity.

Baltasar Gracián