4) "Julia Annas has affirmed that the kind of modern moral skepticism which denies the existence of objective moral values is essentially ‘local’; this means that it is based upon a world-view that is itself immune to skepticism. Richard Bett, on the contrary, has maintained that being non-skeptical about some view of the world is not an indispensable condition for rejecting moral realism."
This the abstract of the paper. Is it ok to use the present perfect, or should I rather employ the simple past? PP seems OK to me. I don't recommend simple past. It tends to suggest that they may hold a different view today.
You could also use simple present when talking of beliefs and positoions in this way. For example, you could 'Aristotle maintains that ....' even though he is long dead.
5) "Several authors have adopted Mackie’s kind of moral skepticism. Among them are Snare 1984, Black 1989–1990, and Garner 1990, though the latter prefers to designate his position ‘anti-moral realism’." I'd omit the comma before 'and'.
6) "Unfortunately, there has been no subsequent analysis of the cogency of Bett’s argument against Annas’ position, and hence no further examination of whether or not the latter’s thesis is correct. I believe that such an analysis is still relevant, because ..." Sounds OK
7) "For from the fact that, to be skeptical about morality, one need not be non-skeptical about every other area, Bett invalidly infers that, to be skeptical about morality, one need not be non-skeptical about any other area. That is to say, to deny the objectivity of morality, it is not necessary to have confidence in the objectivity of science and common sense and any other way of looking at the world; but it does not follow from this that, to deny the objectivity of morality, one need not be certain about the objectivity of at least some other way of looking at the world."
Again with this complicated text. The problem I see is that what I first call "area", I afterwards call "way of looking at the world". Yes, I see what you mean. It seems acceptable to me, but then I'm not a philosopher reading this and, presumably, weighing all the subtleties.
8) "To sum up: one can deny the existence of objective moral values without having to be skeptical only about morality or non-skeptical about science; but this denial necessarily presupposes confidence in the objectivity of some view of reality with which moral realism is at odds. Hence, Annas is right when she maintains that modern moral skepticism is essentially local." OK
9) "According to the first ((not sure first what?), “moral values are not real because there is so much dispute about them and no clear way of resolving it”. Hence, in moral inquiry there does not seem to be progress or accumulation of knowledge, in contrast with what happens in other domains of inquiry. Annas points out that the empirical sciences are in this case the preferred model, since..."
10) "Annas’ view is, then, that modern moral skepticism is local because it is based upon a contrast between morality and some other view of the world whose objectivity is not called into question." OK
11) "Thus, though Annas contends that confidence in the objectivity of science is a possible basis for denying the existence of objective moral values, she does not believe that it is the only possibility." OK
12) "Bett opposes the view that moral skepticism’s being local is a sine qua non for holding that there are no objective moral values."
As my use of sine qua non has provoked some discussion, I've thought of the following option:
"Bett opposes the view that, to deny the existence of objective moral values, it is necessary that modern moral skepticism be local." Sounds good to me
I hope these brief comments are of help to you. However, I think you are doing very well on your own!
Clive