Latin in papers

For English II Honors, we had to write an analytical paper about a novel that we recently finished called Siddhartha. My friends and I were editing each other's papers for clarity and analysis. While editing one of my peer's essays, I saw that she used a Latin word to define one of her concepts. The word was persona, which is described as the socially and personally acceptable mask that the individual present to others and, to some degree, to him or herself.