Purdue Online Writing Lab Purdue OWL® College of Liberal Arts
Developing Strong Thesis Statements
Welcome to the Purdue OWL
This page is brought to you by the OWL at Purdue University. When printing this page, you must include the entire legal notice.
Copyright ©1995-2018 by The Writing Lab & The OWL at Purdue and Purdue University. All rights reserved. This material may not be published, reproduced, broadcast, rewritten, or redistributed without permission. Use of this site constitutes acceptance of our terms and conditions of fair use.
The thesis statement or main claim must be debatable
An argumentative or persuasive piece of writing must begin with a debatable thesis or claim. In other words, the thesis must be something that people could reasonably have differing opinions on. If your thesis is something that is generally agreed upon or accepted as fact then there is no reason to try to persuade people.
Example of a non-debatable thesis statement:
This thesis statement is not debatable. First, the word pollution implies that something is bad or negative in some way. Furthermore, all studies agree that pollution is a problem; they simply disagree on the impact it will have or the scope of the problem. No one could reasonably argue that pollution is unambiguously good.
Example of a debatable thesis statement:
This is an example of a debatable thesis because reasonable people could disagree with it. Some people might think that this is how we should spend the nation's money. Others might feel that we should be spending more money on education. Still others could argue that corporations, not the government, should be paying to limit pollution.
Another example of a debatable thesis statement:
In this example there is also room for disagreement between rational individuals. Some citizens might think focusing on recycling programs rather than private automobiles is the most effective strategy.
The thesis needs to be narrow
Although the scope of your paper might seem overwhelming at the start, generally the narrower the thesis the more effective your argument will be. Your thesis or claim must be supported by evidence. The broader your claim is, the more evidence you will need to convince readers that your position is right.
Example of a thesis that is too broad:
There are several reasons this statement is too broad to argue. First, what is included in the category "drugs"? Is the author talking about illegal drug use, recreational drug use (which might include alcohol and cigarettes), or all uses of medication in general? Second, in what ways are drugs detrimental? Is drug use causing deaths (and is the author equating deaths from overdoses and deaths from drug related violence)? Is drug use changing the moral climate or causing the economy to decline? Finally, what does the author mean by "society"? Is the author referring only to America or to the global population? Does the author make any distinction between the effects on children and adults? There are just too many questions that the claim leaves open. The author could not cover all of the topics listed above, yet the generality of the claim leaves all of these possibilities open to debate.
Example of a narrow or focused thesis:
In this example the topic of drugs has been narrowed down to illegal drugs and the detriment has been narrowed down to gang violence. This is a much more manageable topic.
We could narrow each debatable thesis from the previous examples in the following way:
Narrowed debatable thesis 1:
This thesis narrows the scope of the argument by specifying not just the amount of money used but also how the money could actually help to control pollution.
Narrowed debatable thesis 2:
This thesis narrows the scope of the argument by specifying not just what the focus of a national anti-pollution campaign should be but also why this is the appropriate focus.
Qualifiers such as " typically ," " generally ," " usually ," or " on average " also help to limit the scope of your claim by allowing for the almost inevitable exception to the rule.
Types of claims
Claims typically fall into one of four categories. Thinking about how you want to approach your topic, or, in other words, what type of claim you want to make, is one way to focus your thesis on one particular aspect of your broader topic.
Claims of fact or definition: These claims argue about what the definition of something is or whether something is a settled fact. Example:
Claims of cause and effect: These claims argue that one person, thing, or event caused another thing or event to occur. Example:
Claims about value: These are claims made of what something is worth, whether we value it or not, how we would rate or categorize something. Example:
Claims about solutions or policies: These are claims that argue for or against a certain solution or policy approach to a problem. Example:
Which type of claim is right for your argument? Which type of thesis or claim you use for your argument will depend on your position and knowledge of the topic, your audience, and the context of your paper. You might want to think about where you imagine your audience to be on this topic and pinpoint where you think the biggest difference in viewpoints might be. Even if you start with one type of claim you probably will be using several within the paper. Regardless of the type of claim you choose to utilize it is key to identify the controversy or debate you are addressing and to define your position early on in the paper.
While Sandel argues that pursuing perfection through genetic engineering would decrease our sense of humility, he claims that the sense of solidarity we would lose is also important.
This thesis summarizes several points in Sandel’s argument, but it does not make a claim about how we should understand his argument. A reader who read Sandel’s argument would not also need to read an essay based on this descriptive thesis.
Broad thesis (arguable, but difficult to support with evidence)
Michael Sandel’s arguments about genetic engineering do not take into consideration all the relevant issues.
This is an arguable claim because it would be possible to argue against it by saying that Michael Sandel’s arguments do take all of the relevant issues into consideration. But the claim is too broad. Because the thesis does not specify which “issues” it is focused on—or why it matters if they are considered—readers won’t know what the rest of the essay will argue, and the writer won’t know what to focus on. If there is a particular issue that Sandel does not address, then a more specific version of the thesis would include that issue—hand an explanation of why it is important.
Arguable thesis with analytical claim
While Sandel argues persuasively that our instinct to “remake” (54) ourselves into something ever more perfect is a problem, his belief that we can always draw a line between what is medically necessary and what makes us simply “better than well” (51) is less convincing.
This is an arguable analytical claim. To argue for this claim, the essay writer will need to show how evidence from the article itself points to this interpretation. It’s also a reasonable scope for a thesis because it can be supported with evidence available in the text and is neither too broad nor too narrow.
Arguable thesis with normative claim
Given Sandel’s argument against genetic enhancement, we should not allow parents to decide on using Human Growth Hormone for their children.
This thesis tells us what we should do about a particular issue discussed in Sandel’s article, but it does not tell us how we should understand Sandel’s argument.
Questions to ask about your thesis
- Is the thesis truly arguable? Does it speak to a genuine dilemma in the source, or would most readers automatically agree with it?
- Is the thesis too obvious? Again, would most or all readers agree with it without needing to see your argument?
- Is the thesis complex enough to require a whole essay's worth of argument?
- Is the thesis supportable with evidence from the text rather than with generalizations or outside research?
- Would anyone want to read a paper in which this thesis was developed? That is, can you explain what this paper is adding to our understanding of a problem, question, or topic?
- picture_as_pdf Thesis
IMAGES
VIDEO