I've been inspired to write about Self-Determination Theory (SDT), which is a great theory about how we experience motivation. It has a lot of intricacies, so this will just be a brief overview.
The work started with Edward Deci in 1971 and has grown with the important contributions of other scholars like Richard Ryan.
Basically, the theory drives the idea that intrinsic motivation is the strongest form of motivation. Intrinsic motivation is the drive to seek satisfaction, which often comes from personal growth and having needs met. These needs are: autonomy, competence, and relatedness. Autonomy is the freedom to have a sense of being able to do what you want to do and feel like you should be able to do; Competence is that sense of self-efficacy where you feel good about what you DO and the desire to continue to improve; and relatedness is all about having positive relationships and a sense of belonging with others.
This theory basically breaks motivation down into 2 types of motivation: Intrinsic and Extrinsic. While intrinsic refers to the type of motivation in which a person is driven from the inside, and extrinsic refers to rewards coming from outside a person. Extrinsic rewards include things like praise and a paycheck. The theory states that the more someone is driven by motivating factors outside of themselves, the more likely their motivation is going to die off.
A lot of people argue that not all employees are going to find intrinsic motivation in what they do for work. Many employees who don't have a calling are seeking a paycheck so that they can pursue the things that give them satisfaction outside of work. For instance, an accountant might not feel any satisfaction from balancing accounts for a company, but s/he is working for that paycheck that will let him/her ride that motorcycle on the weekend and take a nice vacation.
That's fine - not everyone is following a calling and finding intrinsic motivation in the work they actually do. But a lot of companies don't realize that employees can be given intrinsic motivators through other parts of their company. The employee doesn't have to find meaning or satisfaction in the actual job they do, but often finds those things in the organizational environment itself.
For instance, I knew a software engineer at a Fortune 500 company who saw his job as an opportunity for the organization to "rent my brain" (as he put it) in exchange for a paycheck. He didn't seem to care much for being at that company.... except for when it came to his coworkers. He felt a sense of belonging with them and loved trying to help them where he could. If his management hadn't destroyed his ability to feel a sense of competence and autonomy in what he did, he might not have planned to depart the company as soon as he could. That sense of belonging motivated him and kept him hanging on, but his experiences with management had soured so much that his main external motivator - the paycheck - eventually did not become enough to keep him hanging around.
So that's the point - an employee may feel indifferent to what they do. However, with the power of meeting employees' intrinsic needs, companies can alter WHY they do it, WHERE they do it, and especially HOW they do it. An employee could be putting in bare minimum and planning to leave because those external "carrots" just aren't enough to leave them feeling intrinsically motivated.
An employee doesn't have to follow a calling or be passionate about their actual job in order to perform well. They need to feel a sense of freedom, competence, and belonging - which a company can provide for them when it genuinely cares about its workers.