Let's say that science doesn't try to analyze those parts of the world not accessible to empirical observation. That could be described as modesty or reticence.

> This is a quite big assumption, and has none to do with describing "the world as it is".

Those who do try to describe the non-material world have a pretty terrible record for reliable results.

by "rest", I assume you are a scientologist talking about theatans.

"This is a quite big assumption, and has none to do with describing "the world as it is"."

I disagree, my favorite thing about the scientific method is that it does its best to drop assumptions. I am not a scientist, but resort to this kind of thinking when I have to debug code. Suggest a better way and I will try it out.