What does "一概而论“ mean？ I’m getting mixed answers to what 一概而论  actually means. What would you translate this sentence as

但是， 我们不能将这位作者的观点一概而论。 

Is this the only way it can be used?
Your sentence translates as:

But we cannot generalize the standpoint of this author. 

It is most often used together with 不能 or 不可 (i.e. in negative sentences, observe the 不 in both cases) or even as a noun, e.g. 这样的一概而论: Such generalization/This kind of generalization.