Thaluikhain said:
As an aside, in that scene there doesn't seem to be much of anyone within 100m of Denethor except Gandalf, nobody would be able to hear what is being said. They just watched some foreign wizard beat up the steward of Gondor for no reason.
To geek out for a minute, there aren't really any "wizards", foreign or domestic in middle-earth. It isn't a profession or the like. There are only a tiny number of them, such as Radagast the Brown, Saruman the White/Many Coloured and Gandalf the Grey/White. There are some others who don't play a significant role in LotR. They are not magical men however, they are Maiar, mystical and immortal beings of the same ilk as Sauron and the Balrog. Gandalf was one of the Istari, a Maiar put into human form so they could help Middle Earth.
It's not an accurate analogy, but it's not entirely dissimilar from in our mythology, if an Angel was sent from Heaven to walk on Earth, that's the kinda figure Gandalf is, tho as I said that's not entirely accurate. It could also be thought of as if one of the Greek pantheon walked among us, like Hercules, Apollo, etc. They have similar "domains" like Beauty, War, the Underworld, etc.
The point is, Gandalf isn't a random magic dude with a long beard and a funny hat. Tho he certainly looks like one. There are only a handful like him in the world, they are very powerful beings and would be living figures of history and legend. I imagine everyone will know who they are.