A Writer's Reference for How to Write a Thesis Statement

The thesis statement is the make-or-break part of any academic paper. Your thesis is a single, declarative statement that works to prove your main idea by the end of your paper. Your thesis statement is your ultimate point. Purdue University's Online Writing Lab states that a thesis "should cover only what you will discuss in your paper and should be supported with specific evidence."

All academic and rhetorical papers are persuasive in tone, content and examples. So, formulate a thesis that can prove your point. A thesis should always be an active, forthright statement. Just listing your opinions essentially proves nothing, whereas research and examples that a reader can relate to will definitely prove your point(s). For example, say that you wanted to write a paper about the health benefits of exercise. Pick just one specific type of exercise and one benefit of this exercise type, like: "Running is beneficial for depression because both physical activity and being out in nature increase runners' serotonin levels." This statement is much more specific, and -- important for any thesis -- it focuses on the why and how aspects of argumentation.

If you're writing an argumentative or research paper about ethical food choices, for example, write a strong, declarative statement, like: "Local, farm-raised beef is healthier for consumers because it does not contain all the pollutants and chemicals that processed meat does." This statement is easily debatable and therefore piques reader interest to find out all of your argumentative points. Then, the rest of your paper will work toward proving this statement with ample research sources and examples. For this particular paper, you might cite research from sources that have published scientific studies about the health benefits of eating farm-raised food or research that discusses the health risks of eating processed food. These citations would help to prove your main point.

Literary analysis papers -- another type of academic paper for which you might need to write a thesis -- also need a strong, declarative statement that you can prove. Don't write "Did Lady Macbeth go insane because she was guilty?" This is a rhetorical question that your reader obviously will not answer for you. Instead, write, "Lady Macbeth's mental decline occurred because she could not handle her guilt after urging her husband to kill King Duncan." Although this statement is indeed arguable, it is a strong declaration that you can prove with examples from the text, Shakespeare's classic play "Macbeth."

You will usually need to revise your thesis statement once you have finished your paper. Oftentimes students intend to prove one main idea in their papers, but this main idea morphs into a slightly different point once they have written the paper. The University of Wisconsin-Madison's Writing Center urges students to revise as needed: "Change your thesis as your paper evolves, because you do not want your thesis to promise more than your paper actually delivers." If you change your point, change your thesis, too, since these should be one in the same.

For example, take the original thesis statement: "Running is beneficial for depression because both physical activity and being out in nature increase hikers' serotonin levels." You may find after writing the paper that you discussed and gave examples about how physical activity increases runners' serotonin levels, but you did not cover how being out in nature assists with depression. To compensate, you should shorten your thesis to: "Running is beneficial for depression because physical activity increases runners' serotonin levels."