As there has seem to be a bit confusion about writing an academic essay and how it should be structured, please note that the essay is a rather free form genre of writing. The text should be academic, well-argued, properly referenced (whenever author refers to the literature and does not present his/her own interpretations, with a clear problem statement and a conclusion that ‘answers’ the problem or question presented in the beginning. Otherwise you are rather free to select a structure that suits what you are about to write and how you like to argue your case.
If you think you need further advice, a good and very comprehensive source can be found at the University of Toronto at http://www.writing.utoronto.ca/advice/general/general-advice