three obscurations

Erik, The term shes sgrib seems to have two connotations:

1. obstruction to omniscience (is the shes bya here referring to "what is to be known", i.e., omniscience?)

2. cognitive obscuration (is the shes bya here referring to cognition and thus taken in a negative sense?)

I've always been puzzled by this.

Thanks, --Gerry

[Erik:] I always understood that the first connotation was its function while the second was its identity. Therefore, to translate something as "that which does such and such" could be correct, but then again, what would "obstructions to omniscience" be in Tibetan?