In the unlikely event that anyone on this spot cares enough about Wilson to read this :P , here's an extract from the link "Difficult Characters" written by Doris Egan (one of the writers of House MD), in which she writes a few things about Wilson's character. The complete article also includes analysis of characters from different stories she has written.
In a novel, it would be easy to lay out [a character's] thoughts. In a visual medium, the viewer has to do the work themselves, and here's the problem: we're used to there only being one answer.
Take Wilson, a complex character on House. He's introduced as (1) a married womanizer (and therefore, by definition, a betrayer) and (2) someone who can't stop caring about people. I loved that two traits we don't normally find in the same character were there in him; it gave him a reality I miss on television. In "House vs. God," we learn that he drove a terminal patient home when her ride didn't show up, stayed to get her groceries when he saw she was too sick to go out, and then, just stayed. A glaring ethical violation for a doctor.
In my mind, Grace was glad he was there. I imagined what it would be like to go through cancer treatment, knowing you were terminal, without any support. What do people do who don't have families, or money to hire help? It might even have crossed her mind that she was using him. (Though she was very fond of him, and knew he was of her. I would use the word "love" here, because it applies, but there's too much tendency in our society to read that as "one, true romantic love.")
House, upon learning of this, calls Wilson an "emotional vampire," who feeds off others' need. That's why, House says, that Wilson is one of the few oncologists who thrives instead of burning out under the burdens of his practice. And perhaps that's true, on one level; but we also know that House likes to present motivations in the darkest possible light. Is it so horrible to need to be needed? That's the kind of drive that calls people to volunteer in the Peace Corps, to become firefighters, to risk their lives for others -- to become an oncologist, and make the lives of many people better than they were before they met him.
Does any of this mean that Wilson didn't violate an ethical standard? And an ethical standard that's there for a very good reason, to boot. He betrayed himself, medicine, and an ideal of behavior.
And I believe Grace was very glad he did it.
Can't all these things be true? Must it be only one answer?
Can't being a manipulative liar who needs to be needed be Wilson's superpower, if he puts it in the service of heroism the best he knows how?
At the end of "Finding Judas," Wilson goes to Tritter to give evidence against House. Why did he do it? Because House, under prolonged psychological pressure (remember the Lenny Bruce story), coupled with drug deprivation, was coming apart? Because something had to be done to put an end to this, one way or another, and House clearly wasn't going to do it? Because he nearly cut a girl in half? Or because he punched Chase? Or because Chase looked angry enough to go to Tritter himself, and if Wilson beat him to the punch, he could negotiate a more reasonable deal that might get them all off the hook?
Can't all these things be true? Must there be only one "real" answer?
