Many students have the mistaken assumption that having an argument or thesis means they have to prove that some professional academic who wrote a book is wrong about his own specialty (an obviously impossible task for an undergraduate writing a short paper under strict time constraints). Such students often conclude that the expectation of having an argument in every paper is ridiculous, and they give up before they’ve even started writing the paper.No professor (unless they really are crazy, of course) expects you to become an expert in a subject overnight, nor to refute in a short essay ideas that were developed over years by an expert with access to all the original sources.
What they do expect is that you direct your very able and unique mind to the text and ask important, worthwhile questions. You should then explore those questions, and posit some possible answers, based on nothing more than your careful reading of the text and your reasoning.
Every book, no matter how carefully researched or how famous its author, rests on certain assumptions, is limited in scope, and is derived from some finite set of sources. Your job when asked to review or critique a work of scholarship is to examine its assumptions, limits, and use of sources, and from these to understand the goals of the work, and to assess how effectively it met its goals. Then, ask yourself what else could have been done, or should be done next, to further our collective understanding of this subject.
Once you have explored all these ideas, you ought to have come to some sort of conclusions of your own about the value of the work for various purposes, and what remains to be explored. These conclusions should be articulated as your thesis, and you will support this thesis with arguments grounded in the text to illustrate why your reading of it is fair and accurate. A critical review is not the same as a bad review.
A closely related problem that many students have is the idea that, as an author of a paper, a student has to at least pretend to know everything about the subject.
Actually, you really ought not to pretend anything, as an author (unless of course you’re writing fiction). What you should do is research and think about your topic as thoroughly as you can within the scope of a given project, and reflect that reading and thinking accurately on the page. Nothing more, and nothing less.
If comments you receive on your writing suggest to you that you are supposed to “know everything about the subject,” what it probably really means is that you did not do as much reading or as much thinking as the assignment required, or that the reading and thinking you did do somehow did not make its way onto the page. Look at your syllabus again, and/or the assignment sheet. Did you carefully read everything that was required for the assignment? Did you do everything the assignment asked of you?
In almost every case, when a student throws up her hands, saying the professor expects too much, that student did not fail to write a truly original, publishable paper. Such a paper was never expected. What is most likely is that the student simply failed to carefully understand the course materials and requirements. The latter is a perfectly reasonable expectation.