Second Law Of Power
 

NEVER PUT TOO MUCH TRUST IN FRIENDS, LEARN HOW TO USE ENEMIES

Be wary of friends - they will betray you more quickly, for they are easily aroused to envy. They also become spoiled and tyrannical. But hire a former enemy and he will be more loyal than a friend, because he has more to prove. In fact you have more to fear from friends than from enemies. If you have no enemies, find a way to make them.

Okay, now this one scares me - LOL

This one is kinda different but it works.

When I was involved with Student Government I'd always try a get the people that lost the election to be a part of the staff. This way they had to put up or shut up. Either they were in it for the Student Body or for their resume.

It 'forced' them in essence to do better cuz if they failed it would affirm the student's initial decision that they weren't the best person for the job.

I haven't had a chance to try this out in a workplace.

Yes, I can see it in the scenario you stated--keep the enemy close. In fact, I have advised electoral winners in my sorority to do the same thing. But I do wonder how it would play out in the workplace.

I don't think it would work in a job setting.