Academic Essays in English

As an English major, the college essays that I have thus-far written for my field have all been based on other people's work.  The topic may be as specific as a single poem, or cover several different works of literature, but the point is to make an argument about a specific idea or theme found in the work(s) being written about.  The style is very detached; while I am putting forth my own opinion, I still need to write in an unemotional way, basing my statements on quotations and facts.  The paper is my own interpretation of the work(s) involved, and it is written to be -- if not outright persuasive -- at least a sound argument.  Still, everything is far more clinical than, for example, the Jonathan Lethem essay that we read in class, "The Ecstasy of Influence: A Plagiarism."  Like an academic essay on English literature, Lethem made an argument and supported it with literary examples, but his tone was far warmer and more informal that both anything I have found myself called upon to write and the vast majority of academic essays that I have read -- though it was similar to non-fiction books, which generally have more of their authors' personalities than do essays.