The claim is not simply that disciplinary expertise confers moral and political superiority, but that historians, because of their training, are uniquely objective observers: “As historians, we consider diverse viewpoints while acknowledging our own limitations and subjectivity.”
I used Oxford Advanced Learner Dictionary 8 and Macmillan Dictinonary for the word disciplinary. And they both produce the same result: "connected with the punishment of people who do not obey rules". This meaning really confuses me, actually I think it's not correspondent to the whole meaning of the sentence, I mean if I think "disciplinary expertise" is the same as "high level-knowledge", the sentence is more clearer. But why two famous Dictionaries produce like that? Can anyone help me out?