Actually, I don't consider McPherson a God... yes he has an opinion and it is interjected in his writing as is Sword or any other author but how much it colors their analysis... that is the difference between a Lost Cause Author and a historian. The day I come across a Lost Causer who has done even a 10th of the research he has... maybe I'll give them their worth. I consider DiLorenzo, the Kennedy bros etc as Lost Cause Authors. Of them all I regard the Kennedy Bros w/ the most respect. At least they have the integrity to declare their bias and don't really go out of their way to hide their agenda and I do believe some of their views have a valid point. While Dilorenzo is below contempt; he hides his lies, mischaracterizations, misquotes etc... or tries to.
Using any source the reader has to realize that there is an agenda... think I'm wrong? Read any issue of the NY Times from 1860-the present, pick out the bias and the agenda; it isn't difficult. Watch the news, read books. Everyone has a bias, do they use their position to try and decieve or try to hide their bias? That is the question one must ask about an author before deciding if he/she is legit.
I am no professional author, yet I know far more about some aspects of the War than some Professional Authors. I all but guarantee you that members here like Gary know far more about the arms used in the War than a pro historian like McPherson. Hence why there is the advantage of a Pro historian when errors are pointed out w/ valid research showing them as an error those errors are corrected.
If at the end of a book you have the distinct impression maybe the author would like a return to the good old days of slavery... hmmm. I do believe there might just be an agenda or what I might call a negative bias. If you finish a book on the CS and come to the realization that the author is praising the CS only so that he might further slander the US = agenda. As I've said often, Lost Causer does not equal Southerner or proud member of the SCV etc. What it does equal is someone willing to distort or outright lie to make the South look better at the expense of the rest of the country.