Scientists establish a link between religious fundamentalism and brain damage

[Major Nikon]

12. Scientific theories generally aren't even intended to be factual

A fact is something that can be proved. A scientific theory is more of a practical model which explains something in a useful way. It works for all testable applications, but it's only proven for the things you can test it against.

In other words let's say I have a theory that says all grass is green because every blade ever observed is green. It stands to reason every new hybrid or varietal of grass will also be green, but it does not mean there will never be an eventual one that will be a different color because I have no way to prove this to be always true.