Who decides that a piece of work is "art"? A group of people defining themselves as artists or art critics.
Who decides a theory is valid? A group of people defining themselves as scientists.
Don't jump on me! Not yet, at least. Let me finish.
I agree that "science" operates in a way more formally than, say, art. But there are many things accepted as incontrovertible truth by the scientific community without proof that they are actually true. True, they found big bones of giant reptiles. This proves dinosaurs existed. But how can they, just from the bones, decide the color of their skins, their cries, their social behaviour.
And that applies to many other scientific fields. As DBK said, the general consensus determines scientific truth.
But how often has science been wrong? Look at a simple thing like the atom. How many times have we discovered that we could split it into smaller and smaller pieces?
So, saying creationism and natural science are not on the same level because the former is not "exact" is wrong.
However, I do believe they are actually NOT on the same level.
Creationism is the history of what God made.
Natural science is the study of the rules God used to create.
The one does not exclude the other. It is like comparing history with physics.
