You want to try and bring a character to life in an honest a way as you possibly can. It doesn't matter whether he's a doctor, an actor, a car salesman or a captain of a starship. If you can bring truth and honesty to that character, then your audience will believe you.
“I think computer viruses should count as life. I think it says something about human nature that the only form of life we have created so far is purely destructive. We've created life in our own image.”