Rule 1: Keep them too busy to think. Thinking is dangerous. If people can stop and think about their situation logically, they might realize how crazy things are.
Rule 2: Keep them tired. This is a corollary to keeping them too busy to think. Of course you can’t turn off anyone’s thought processes completely—but you can keep them too tired to do any original thinking. The decision center in the brain tires out just like a muscle, and when it’s exhausted, people start making certain predictable types of logic mistakes. Found a system based on those mistakes, and you’re golden.
Exhaustion is also the perfect defense against any good thinking that might slip through. Fixing the system requires change, and change requires effort, and effort requires energy that just isn’t there. No energy, and your lover’s dangerous epiphany is converted into nothing but a couple of boring fights.
Rule 3: Keep them emotionally involved. Make them love you if you can, or if you’re a company, foster a company culture of extreme loyalty. Otherwise, tie their success to yours, so if you do well, they do well, and if you fail, they fail. If you’re working in an industry where failure isn’t a possibility (the government, utilities), establish a status system where workers do better or worse based on seniority. (This also works in bad relationships if you’re polyamorous.)
Also note that if you set up a system in which personal loyalty and devotion are proof of your lover’s worthiness as a person, you can make people love you. Or at least think they love you. In fact, any combination of intermittent rewards plus too much exhaustion to consider other alternatives will induce people to think they love you, even if they hate you as well.