An Essay on Criticism is one of the first major poems written by the English writer Alexander Pope (1688–1744). It is the source of the famous quotations "To err is human, to forgive divine," "A little learning is a dang'rous thing" (frequently misquoted as "A little knowledge is a dang'rous thing"), and "Fools rush in where angels fear to tread." It first appeared in 1711  after having been written in 1709, and it is clear from Pope's correspondence  that many of the poem's ideas had existed in prose form since at least 1706. Composed in heroic couplets (pairs of adjacent rhyming lines of iambic pentameter ) and written in the Horatian mode of satire, it is a verse essay primarily concerned with how writers and critics behave in the new literary commerce of Pope's contemporary age. The poem covers a range of good criticism and advice, and represents many of the chief literary ideals of Pope's age.
Looking back through the last page or two, I see that I have made it appear as though my motives in writing were wholly public-spirited. I don't want to leave that as the final impression. All writers are vain, selfish, and lazy, and at the very bottom of their motives there lies a mystery. Writing a book is a horrible, exhausting struggle, like a long bout of some painful illness. One would never undertake such a thing if one were not driven on by some demon whom one can neither resist nor understand. For all one knows that demon is simply the same instinct that makes a baby squall for attention. And yet it is also true that one can write nothing readable unless one constantly struggles to efface one's own personality. Good prose is like a windowpane. I cannot say with certainty which of my motives are the strongest, but I know which of them deserve to be followed. And looking back through my work, I see that it is invariably where I lacked a political purpose that I wrote lifeless books and was betrayed into purple passages, sentences without meaning, decorative adjectives and humbug generally.
Longer essays may also contain an introductory page that defines words and phrases of the essay's topic. Most academic institutions require that all substantial facts, quotations, and other porting material in an essay be referenced in a bibliography or works cited page at the end of the text. This scholarly convention helps others (whether teachers or fellow scholars) to understand the basis of facts and quotations the author uses to support the essay's argument and helps readers evaluate to what extent the argument is supported by evidence, and to evaluate the quality of that evidence. The academic essay tests the student's ability to present their thoughts in an organized way and is designed to test their intellectual capabilities.