Doubts about the grammar of a paragraph

"L.K., too, has seen that the ethical skepticism espoused by, among others, M. and H. is local, even though he does not couch it in these terms. According to him, these skeptics 'suggest that because of science, especially the social sciences, morality does not provide the best explanation of human conduct or belief'. That is to say, morality is rejected because moral explanation conflicts with scientific explanation, which is the best available."

Is the whole thing clear? I don't feel entirely comfortable with the last sentence.

Thanks

Sextus