In 1943, Abraham Maslow first introduced his Hierarchy of Needs theory, which examines what motivates us as individuals.
He claimed that people are motivated by things and circumstances ranging from basic survival up to the ability to reach and achieve one's full potential.
That sounds like something that could be applied in the workplace to elevate employees' motivation from simply being there to get a paycheck to performing at a very high level...
...and actually enjoy doing it.