I agree with Jeff Jarvis that journalism is something you do, not who you are:
Journalism is not defined by the person who does it or by the medium or the company that delivers it.
Journalism is not a thing. It is an act: The act of informing is journalism. It’s a verb, not a noun.
But his grammar needs a little work. An “act” is still a thing, and therefore a noun.
I won’t let that detract from his thoughts though, because I get his point. I too harbor that inner desire to “aggregate, select, edit, present, and distribute information” in order to affect people, and to make a difference in the world. So am I a journalist or not? I guess if I achieve that goal then I am. If not, I’ll just keep trying.
To want to make a difference. Okay, maybe it is a verb.