What do you call it when something's worth is two things at the same time?

Example:

From the movie Kingdom of Heaven

Balian of Ibelin: What is Jerusalem worth?

Saladin: Nothing. ... Everything!

What lesson did Saladin teach Balien? _____

Balian returned to Europe reflecting on this lesson of _____ that Saladin taught him. How hundreds of years of religious wars over a piece of land and hundreds of thousands of deaths can be seen as _____ .

What I thought of:

From my understanding this is the juxtaposition between Jerusalem being worthless desert and great spiritual significance to religion at same time.

Is the lesson he learnt transcendence perhaps?

Worth two things at the same time is a Duality. See bottom paragraph. In this case Duality of value.

Perspective is a good word that may describe Saladin's view but not his experience. It must have been near the climax of the film to ask such a profound question. The lesson must be profound or you have wasted your ninety minutes. If we can't entertain words for such profundities we can't very well boast of our literacy.

By "Nothing and everything." he is telling us his experience of Jerusalem. The two extremes coming together make an important duality, such as the definition of God as 'an infinite sphere, whose centre is everywhere and whose circumference is nowhere'.

In this case his experience has been seeing friends struggle and die for the advantage of a few extra square feet of territory that's just like any patch of dirt one hundred miles in any direction. Like so many things of purported value it may not turn out to be worth what it actually cost you. You find that out after you see what you can really do with it once you've got it.

I think the right term would start from the original question of "What is it worth?" The answer should be Value. The meaning behind the answer, Value, would be as loaded and open to interpretation as any other you could think of. It would remind the victory minded of their great glory and the more sober minded of their terrible cost. The range of these answers bring forth the duality.

Your thoughts are interesting but the word juxtaposition makes me think of the meaning switching from one to another; only one at a time. What Jerusalem means is both and at the very same time. Both the worthless desert and its great spiritual significance to religion. The duality is vital to its true value.

He taught him humility. Doesn't all this religious stuff boil down to that? But in terms of two opposites: the lesson of things not always being what they seem.

That is, reality is paradoxical, a paradox.

two opposite situations: worthless dessert/great spiritual significance

Paradox: Merriam Webster:

c: an argument that apparently derives self-contradictory conclusions by valid deduction from acceptable premises

this lesson on paradox