I think that this is one of David's best descriptions of his craft ever:
"Patrick Stewart has talked about how one of the reasons he keeps being asked to play these iconic science fiction characters is that the training that he has through Royal Shakespeare allows him to give it a gravity and a reality, so it's not just silly men in funny suits.
Well, there's a similar trick - "trick" is underplaying it a bit - to playing Shakepseare and to playing this kind of work: you've got to play it absolutely real. But the language of Shakespeare is slightly heightened, and you have to serve it up. And there's a similar thing to that science-fiction/fantasy stuff, and you have to absolutely ground it in veracity, and yet just serve it up a little bit. I completely get what Patrick says, and I'm sure Ian McKellen might admit to a similar thing. If you can sell that you're the King of Scotland, or Henry V on a tiny stage in a studio theater somewhere, then you can probably sell that you're a starship captain or a time traveler. There is a similar skill there, yeah."
In an interview with Alan Sepinwall - December 24 2009 - on the American website NJ.com