Though provoking question

If you stole my pen and told me you’d return it if I guessed what you were going to do with it, would you return it if I guess you’d never return it?

Actually I phrased the heading poorly. It's more of a paradoxical question than a thought provoking one.

Famousdebater: Lol, that's weird.

But yes, i'd give it back, I think stealing is wrong.

ColeTrain: I suppose that this is a logical answer but it still doesn't escape the problems the question poses. 😉

Well, if I borrow something from someone then I'll return it, very simple.

lannan13: But that isn't what the question stated. It clearly said:

If you stole my pen

And if your philosophy is that you'd return it then remember that it says "if", so we'll assume that you did steal it and this situation did happen because this is the way that the question is posed.

Famousdebater: Haha, true

Famousdebater: If you stole my pen and told me you’d return it if I guessed what you were going to do with it, would you return it if I guess you’d never return it?
No, because you didn't guess what I was gonna do with it.

Bi0Hazard: But if you didn't return it to me, then I guessed correctly that you wouldn't return it to me - which would mean that you'd have to return it to me, but then that'd mean I guessed incorrectly, etc. 😉

Famousdebater: But if you didn't return it to me, then I guessed correctly that you wouldn't return it to me
That is IF I would never return it, but I said I would if you guessed correctly what I am going to do with it. You can just guess that I would never return it and leave it at that, but I still wouldn't have to return it since I told you that I would return it IF you correctly guessed what I am going to do with it, and saying that I would never return it is not guessing what I was going to do with it(it is guessing what I won't do).

Bi0Hazard: saying that I would never return it is not guessing what I was going to do with it(it is guessing what I won't do).

I guess I could have phrased the OP more specifically.