He is not 'capable of' making those medical decisions himself. [=he cannot make the decisions by himself because he cannot think clearly, he is too sick, etc.]
I don't believe that she's 'capable of' murder. [=that she is the kind of person who could murder someone]
She is one of the most 'capable' [='skilled'] and versatile actresses in Hollywood.
(..) What I'm trying to say is that he's a distributor, right? He's a... He's a businessman, he's a man of business. It would therefore seem to follow that he is capable of acting out of mutual self-interest, yes? What? Do you think he is capable of listening to reason? What kind of reason? (..)2008 TvShow: Breaking Bad Title: Cat's in the Bag... Season: 1 Episode 2