Here is a great paragraph from Linchpin, a beautiful book from Seth Godin: I think it gives what can be considered the (right) definition of Knowledge Worker (the artist) … or at least as it should be:

The job is what you do when you are told what to do. The job is showing up at the factory, following instructions, meeting spec, and being managed.

Someone can always do your job a litlle better or faster or cheaper than you can.

The job might be difficult, it might require skill, but it’s a job.

Your art is waht you do when no one can tell you exactly how to do it. Your art is the act of taking personal responsibility, challengin the status quo, and changing people.

I call the process of doing you art “the work”. It’s possible to have a job and do the work too. In fact, that’s how you become a linchpin.

The job is not the work.