Redundancy caused by the peculiar structure of a sentence

Question

This is from "The Call of Cthulhu" by H.P. Lovecraft:

The most merciful thing in the world, I think, is the inability of the human mind to correlate all its contents. We live on a placid island of ignorance in the midst of black seas of infinity, and it was not meant that we should voyage far. The sciences, each straining in its own direction, have hitherto harmed us little; but some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the light into the peace and safety of a new dark age.

It seems that "and of our frightful position therein" stands for "and terrifying vistas of our frightful position therein", However, it seems a bit improper, because we're basically saying "but some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality and will open up such terrifying vistas of our frightful position therein.", which is extremely redundant, and perhaps ungrammatical. Is this the case? What do you think about this?

Answer 1

The grammar is OK, and it doesn't seem redundant to me.

In the bolded phrase, "therein" refers to "reality", the noun right before the beginning of that phrase. So the phrase actually means, "and of our frightful position in reality". And the whole sentence has the meaning:

"... but some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position in reality, ..."

The terrifying vistas are of two different things, of "reality" and of "our position (in it)."