When writing papers I find that I consistently use "that" in sentences where I describe a perspective held by an author. For example, I wrote
From what I have presented thus far, it should be clear that Hume argues that reason has no role in moral determinations, and that the sentiments from which moral determinations are drawn are those universal, intrinsic aspects of human nature.
It sometimes feels awkward having two successive "that"'s, such as "it should be clear that Hume argues that ...".
In contrast, the forthcoming sentence seems to be grammatically correct (at least according to my limited knowledge), and perhaps flows better:
"From what I have presented thus far, it should be clear Hume argues reason has no role in moral determinations, and the sentiments from which moral determinations are drawn are those universal, intrinsic aspects of human nature"
However, I'm wondering whether a "that" is better inserted before "the sentiments...", reading "it should be clear Hume argues reason has no role in moral determinations, and that the sentiments from which moral." Alternatively, should a "that" be inserted before "Hume" if the previous "that" is inserted before "the sentiments"?
In general, why is it the case that I feel compelled to load up sentences with "that"'s like this, and which is the better option; leaving them in, or taking them all out?