No, you don't engage in a direct dialog, because no game can ever be as comprehensive as reality. I know we think computers are brilliant and all, but they still do not come close to the quickness or complexity of the human brain. So the dialog is alway pre-scripted. You are only given certain options for response because there's no way all options can be programmed for the computer to respond to, and there can only be certain options for the computer's response. So again, you are trying to "figure out" the game. What does it want? What will it respond to? It's like trying to figure out what combination of words will give you the search results you want in Google because computers are nothing but cold equations that only understand what they're told to understand and only in the way they're told to understand it. Case in point: put "金城 武" into Bablefish and translate from Japanese to English and you'll get "kangai military affairs." Put the same combination into Google and you'll get "Takeshi Kaneshiro" which is actually correct. No one's told Bablefish to translate kanji as names. A computer is only as comprehensive as it's told to be.
I realize that's a rather limited example, but due to the scripted nature that games must take, I can't see any real dialog regarding "hard questions." You'll only get the answers that have been programmed into the game. You are still only talking to a computer that can only do what it's been told to do. It's just as "one-sided" as a movie or novel, there's just this illusion of interactivity because every once and a while you are presented with some dilemma--chosen by programmers--and possible responses, again, chosen by programmers. If you feel somehow "in control" or autonomous regarding your actions, then kudos to the designers. They've clearly done their jobs well.
Again, the game cannot do more raise questions, but in the end it's the questions that are interesting. Playing a game that asks the questions, though, is no different than seeing a movie or reading a novel on the same subject. You are still left with someone else's ideas about the subject, just explored in a different way.