"Much greater extent"

Looks fine to me. "Much greater extent" implies a stronger constrast. As a stronger contrast, it makes for better reading, but it would also require more rigorous proof in your paper.

Though "to a greater extent" already implies that there's some way of measuring how "science" on the one hand and "morality" on the other "ensure such knowledge".

MrP

I'm not entirely sure that I've fully got your point.

What if I say

"On the other hand, it may be argued that even though science has not been entirely successful in providing an objective knowledge of reality, its procedures can ensure such knowledge to a much greater extent than the procedures of moral argument could." ?

Sextus

I think I'd probably leave out the "much". It seems over-exact; as if someone has the figures to show that science's provision of objective knowledge of reality is quantifiably greater than morality's!

MrP

So, apart from "much" (which I'll leave out), is the new version correct?

Sextus

I would probably say:

"On the other hand, it might be argued that even though science has not been entirely successful in providing an objective knowledge of reality, its procedures can ensure such knowledge to a greater extent than the procedures of moral argument." ?

MrP