History: Weighing Views and Objectivity

I just finished Six Encounters with Lincoln by Elizabeth Brown Pryor.  It was not the easiest book to read, but it had some insights and I both learned things from it and have had some thoughts.  There's not else to ask from a book, is there? The author seems to want to be critical of Lincoln--and often is--but always comes back to what a great President and man he was.   At times she wants him to be Superman, to fix all the evils of mid-19th Century America.  Besides dealing with the Civil War and keeping the Union together, with the complex problems of slavery and emancipation, with a country full of citizens even more divided than they are today, etc., she is disappointed he didn't provide remedies for Indians, lead the fight for political rights for women, etc.   I was struck by this, never, I guess, really considering it.  "Abraham Lincoln...was never truly President of the entire United States."  And, in fact, he wasn't.  Oh, he never accepted that the Southern states had really left the Union, but the reality is that they did.  (With this in mind, I am reminded of a panel discussion that included two of the best US historians, Joseph Ellis and Sean Willentz.  During the discussion, Willentz made a point.  Ellis went quiet, mulling that over, before admitting, "I didn't know that."  Wait!  Joe Ellis knows everything about early US history......  It was a good lesson for me.) But one of the pitfalls of the book is that the author, in criticizing Lincoln and his policies, seems to give serious credence to all views.  That is, in weighing different sides and their arguments, she makes a mistake in giving equal weight to all of them.  She claims that Lincoln always "missed the point" of the South, as if the Southern position of defending and perpetuating slavery was a valid one.  That Lincoln didn't accept the institution of slavery, just because it was the Southern position, should not be a criticism of him.  He didn't "miss the point," but refused to give credence to it, esp after 1862.   In thinking about giving equal weight/legitimacy to all views, I also wondered about objectivity, particularly in the writing of history. Is a historian required to be "objective?" That is, in writing history, should the author not "take sides?" (I suppose we could also substitute "journalism" for history.) How does/can one be objective when writing history? What does it mean to be objective? And, is being objective a good thing? For instance, how can one be objective when writing about Hitler? What if, in writing an article or book, I describe Hitler as "the biggest monster of the 20th Century?" There are two loaded words in my description. Yes, we can debate whether he or Stalin or Mao was "the biggest." Both of the commies killed more people, but also had more time. But that's a discussion for another day; let's stick with Hitler. The other loaded word is "monster." Is the use of that word being objective? Should I avoid using it? Why? After all, what mother when holding her new-born says, "I hope you become a monster?" It certainly has very negative connotations. But what else do we call someone responsible for the deaths of millions of people and a world war--"St. Adolf?" Do "dictator" or "murderer," even "mass murderer" really tell an accurate story? Does "monster" color me not objective? So, what does being objective mean? I'm not sure. Perhaps it doesn't mean not taking sides, because doing that makes one an accomplice. Maybe it merely means to give each side a hearing. History, Henry Steele Commager once wrote, is "the judgment of the past--and the judgment is important."