The five paragraph essay has an interesting and turbulent history. Long taught as the most handy way to explain the writing process to composition students, it has been both praised and criticized by representatives in higher education. Some professors have found that it limits students by forcing them to express themselves within an artificial structure. Others continue to argue that the five paragraph essay helps students—both in school and in life—by giving them an easy-to-apply device for saying what needs to be said clearly and concisely. Since the vast majority of professors in composition classes teach and encourage the five paragraph essay, it is important for students to understand its structure and usefulness as well as its limitations.
The structure of the five paragraph essay is fairly straightforward, and almost every composition student knows it in theory. The first paragraph introduces the topic, gives a three-sentence outline of the argument to follow, then suggests what the essay's conclusion—its thesis—will be. The next three paragraphs follow through on the first paragraph by restating the topic sentences and offering proof or evidence for the assumptions that support the thesis. Finally, the conclusion paragraph summarizes the argument, reiterates the thesis, and suggests how the thesis relates to a broader idea. The final sentence should be clever, memorable, and relevant.
This, unfortunately, is often the extent of what most composition instructors share with their students. What instructors rarely reveal is that the five paragraph essay has roots much older and more significant than English 1A. Fundamentally, the form is based on a tradition reaching back thousands of years: the tradition of formal logic, established in the West by Aristotle and Plato. Formal logic is the foundation of philosophy, mathematics, computer science, and even music! Most students are perfectly capable of determining whether a statement is "true" or "not true," "valid" or "invalid," which is the core of this structure.
In formal logic, all that is required are premises and conclusions. The premises of a logical argument are those statements which are assumed to be true for the sake of the argument. In the five paragraph essay, the premises of your argument are expressed in your topic sentences. If the statements made in your topic sentences are proven or known to be true, then you already have the makings of a solid essay. The "conclusion" of your essay is simply your "thesis"—what you want to prove based on your premises.
Of course, the five paragraph essay does have limitations. It requires students to have a clear idea of what they want to say in advance. Since you need to know your conclusion before you even start writing, it is vital to use techniques like brainstorming and outlining to clarify your argument and control the logical progression of your essay. In fact, brainstorming and outlining are more important steps to take before writing the five paragraph essay than before writing any other type of essay.

