Casting of Robert Pattinson in ‘Cosmopolis,’ someone whose acting might not be as critically lauded as Mortensen’s, was obviously a well-thought-out decision, then.
Well, Keira’s acting doesn’t always get praise from high-brow critics, either. I would use that parallel. You have a young actor who’s found success with a franchise just like Keira did with ‘Pirates of the Caribbean,’ who’s underrated because of that. In each case, they’re too pretty and too successful so people are jealous. As a result, people assume that they can’t possibly be good actors.

So what was the exact motivation for casting Pattinson in ‘Cosmopolis’?
He’s the right age, he’s got the right screen presence, and when I looked at his other work I thought he’d be really interesting for the role. Casting is a black art – it’s a bit mysterious how you come to these things – and it’s subjective, too, of course. As a director, there are no rules to guide you. You have to go with your gut, ultimately.

Source: Movie Fone