I'm really struggling with a passage in a 12th century manuscript extolling the virtues of studying astrology that I'm working on for my thesis. The sentence is:
De huius utilitate autem superfluum esset agere cum ista hominem super hominem efferens futuraram ac omnium a natura absconditorum precium efficiat.
The previous sentences explained that though its study was hard work, it was worthwhile, and this sentence is expanding on that. I'm confused as to what the subject and object are in the sentence — efficiat seems to be the main verb and I assume that precium (reward) is the object. I'm also assuming that superfluum is a noun (surplus) here, and Whitaker's tells me that agere with cum means "spends time" rather than its usual meaning (though does that mean cum doesn't take the ablative in that case, because I can't see an ablative here?).
My attempt at translating it is pretty muddled — I have something along these lines:
Concerning the usefulness of this surplus would be to spend time so that a man over man brings out the [events of the] future, and all hidden things by birth/nature are its reward.
I think the gist of it is that it's worth spending time studying because the reward is the ability to see hidden and future events, but I'm puzzling about the structure of the sentence.
Hominem super hominem is confusing me in particular — I know super takes the accusative, but why is the first hominem also accusative? Is it somehow the object of efficiat?
Any suggestions very gratefully accepted!