What Is to Be Met Within Space?

The phrase things which are to be met within space can naturally be understood as synonymous with whatever can be met in space. So it's an edge case, right? It's not a thing, but it's still the... Not a material thing is specific. I guess he's drawing that out to try to make a point about numina and the idea that when we think about things external to ourselves, we're thinking about material things. But there are other things that may be relevant here.