English 102

What is a Thesis?

Your final research paper must have a thesis. It is not simply reporting facts. Rather, it is making a case, proving a point, using the facts you research to back up your case. The thesis is the point your paper is trying to prove. Here are some essential points to keep in mind about the thesis, starting with a definition.

Thesis (plural: theses, pronounced THEES-eez): The point that an essay is trying to prove. Also known as the claim or argument. Everything in a persuasive essay relates to the thesis, either as evidence, explanation, elaboration or rebuttal of alternative claims. Think of the thesis as the spine of your paper. Just as all the parts of your body are connected to the spine, and without the spine your body could not stand, so too in your essay all parts must be connected to the thesis, and without the thesis the essay cannot stand. Parts that are not connected must be revised so that they do connect, or else eliminated. A thesis, in other words, is not the same as the thesis statement, which is a sentence or two in your introduction that tells the reader what the thesis is. The thesis is not limited to one spot in your essay; it runs through the whole thing, from start to finish.

A thesis can be expressed as a statement

Because the thesis is what you’re trying to prove, it must be possible to express it in the form of a statement or assertion (e.g., “the sky is blue”). It is not a question (“what color is the sky?”) or a topic (“the color of the sky”). Notice that “The sky is blue” is a complete declarative sentence, while the topic (“the color of the sky”) is not—it does not say anything about the sky’s color.

A thesis is arguable

An arguable thesis is one you have to give reasons for, that is worth proving (i.e., not obvious). So my example above is not a valid thesis, because everybody knows what color the sky is. An arguable thesis might be, for example, “The sky only became blue about 1 billion years ago, when the composition of the atmosphere changed to produce the specific refraction of sunlight that makes it look blue.” (I have no idea if this is true or not, by the way—it’s just an example.) This statement is not obvious, and it would require evidence about the nature of the atmosphere a billion years ago, and explanations of why that evidence is reliable, in order to be proved.

Theses can be statements about matters of fact (e.g., the physical structure of the atom), interpretation (e.g., the true meaning of Hamlet), analysis (e.g., the causes of diabetes), or values (e.g., the morality of the death penalty). In this class theses about values are not allowed. (See below re: prescriptive and descriptive theses). Your paper should make a persuasive case about some question of fact, interpretation or analysis.

Your thesis will answer your research question

Eventually, you will have refined your research question, putting it into a well-focused form that allows you to identify many sources, all dealing with that question in some way—trying to answer it, providing information needed to answer it, trying to answer related questions that shed light on it somehow. Your paper will then attempt to answer this question, and the answer you provide will be your thesis.

Descriptive and prescriptive theses

A descriptive thesis makes a claim about how things are. A prescriptive thesis makes a claim about how things should be. (Think of a doctor’s prescription, which tells you what you should do to get well, as opposed to a diagnosis, which simply describes your illness.) You can agree with someone about how things are even if you don’t share their values. But you can’t agree on how things should be unless you share at least one value. Therefore, prescriptive theses deal with questions of values, ethics or morality. And as I said, such theses are not allowed in this class.

Here are some features of each type of thesis.

A descriptive thesis

A prescriptive thesis also uses evidence, logic, measurement, analysis, interpretation and explanation. However, unlike a descriptive thesis, it also

Some examples of descriptive theses:

Some examples of prescriptive theses:

In some cases a descriptive thesis may strongly imply a prescriptive argument as well (as in most of the examples above). However, note that one can agree or disagree with the descriptive thesis regardless of how one feels about the moral question. For example, some people agree that global warming is real and caused by human activity, but they do not believe it is a bad thing.

Remember: prescriptive theses (theses about values, ethics, morality, or “shoulds”) are not allowed in this class.


Works Cited

Loewen, James. Lies My Teacher Told Me: Everything Your American History Textbook Got Wrong. New York: Touchstone, 1996.