The truism that we each have "our own" opinions misses the point.
A good critical essay acknowledges that many perspectives are possible on any question, yet demonstrates the validity or correctness of the writer's own view.
The writer should demonstrate originality and critical thinking by showing what the question is asking, and why it is important rather than merely repeating it. Many first-year students ask whether the "thesis" is not just their "opinion" of a historical question.
A thesis is indeed a "point of view," or "perspective," but of a particular sort: it is based not only on belief, but on a logical and systematic argument supported by evidence.
Avoid grand statements about humanity in general, and be careful of theories which fit all cases.
Make a point of using evidence with attention to specificity of time and place, i.e.
The footnote is a way of demonstrating the author's thesis against the evidence.
In effect, it is a way of saying: "If you don't accept my thesis, you can check the evidence yourself." If your instructor is unclear about your argument, he or she may very well go back and check how you are using your original sources.
The purpose of this guide is to provide you with the basics for writing undergraduate history essays and papers.
It is a guide only, and its step by step approach is only one possible model; it does not replace consultation with your professor, TA, or instructor about writing questions and getting feedback, nor the excellent tutoring services provided by the Rutgers Writing Center program (room 304, Murray Hall, College Avenue Campus) and the Douglass Writing Center (room 101, Speech and Hearing Building, Douglass Campus). All serious writing is done in drafts with many hesitations, revisions, and new inspirations.