What the correct adjective for this type of person:

* Has his/her mind made up on X subject before he/she talks to you (this fact is not revealed to you until you have dealt with the person enough times, then you learn it by experience; they admit nothing)

* Not only has the person made up his/her mind on X subject but the opinion on X is virtually impossible to budge. Facts won’t work, neither would anecdotes.

* Person asks you what you think about X. The outcomes:
—> You say you think X is a good idea – they will go away, but then if X fails, they will blame you

—> You say you think X is not a good idea and here’s why – they won’t take the answer, will debate you on the why, usually along the lines of “you don’t know that.” They will do that even if you cite facts/figures.

e.g. You: Don’t play with fire because you might get burned.
Person: But you don’t know until you try.

another e.g. You: Don’t play with fire because of the 5 people I know who played with fire, 3 of them got burned badly.
Person: Maybe they were just unlucky
(Yes, I know ths is an absurd e.g. but just using it for illustration)

a 3rd e.g. You: Don’t play with fire because according to a Harvard study, 60% of people who play with fire get burned with half of those being third degree burns.
Person: When was that study from?
You: 1985
Person: Well, maybe things are different now. Maybe the matches we use now are better quality.

* Finally: Best method to deal with the person I learned is Socratic method, but it takes a while and everyone ends up confused.

You: Why do you want to play with fire?
Person: Because it is so bright!
You: Why is being bright important?
Person: Ummm… (might play with fire anyway)

I thought maybe it’s “stubborn,” but my understanding of stubborn is usually someone who has a stance and makes that stance known to you forcefully. Like, to me, stubborn would be like “I’m playing with fire dammit. You are all cowards and don’t want me to have fun.” Here, the person seemingly has an open mind, answering with stuff like “maybe,” “perhaps,” etc. without stating a stance. (Except in the last example but that takes coaxing on your part)