i agree with your point that a good actor can make you forget that but my point stands. acting is, crudely put, pretending to be something the actor is not. by definition it's faking.
alasdair
Again, I don't think that's the case (except for the 'crude' part

). There are a million examples, but here is the one that jumped into my mind: in
Aguirre, Wrath of God Klaus Kinsky plays a complicated, but quite insane conquistador. Now, it's true that Kinsky himself wasn't a conquistador, but he was complicated and he was definitely insane. An actor must put himself into a role in order to play it convincingly.
An actor can play, let's say, a Baker going through a mid-life crisis - in order the play the role convincingly, the actor must tap into his own emotional memory to really understand the person he's playing. If the actor has never experience such emotions, it's likely he won't play the role as well as someone who has. The fact that he's playing a Baker is completely irrelevant because we don't care about his occupation, we care about his personality and how he deals with conflict - if his personality feels disingenuous, the actor has failed to do his job properly. You need to be 'real' as an actor in order to convey certain (genuine) emotions and ideas - whereas implies 'fake' pure artifice. You can act, yet still embody the person you are portraying.
I realize I'm idealizing the acting process a bit, and many of the things I said are completely irrelevant to the modern Hollywood ethos, but the goal of acting is to be as real as possible in a fictional world. Calling it 'fake' is a bit dismissive. It's like calling WWE 'fake' - the stories and characters are all made up, but those people still take a beating, they still have brutal workout regimens, and they put their lives on the line every time they enter the ring. Fake and Real are not necessarily mutually exclusive.