Structuring an argumentative essay or speech can be tricky. Writers have to make important decisions about the type of structure that most benefits the intended audience: Which structure will most effectively help the intended audience understand the topic and accept the given claim or position? One way to make a determination about a work's structure is to try outlining it two ways and then choose the one that will have the greatest impact on a reader: Outline it once using a thesis, and outline it once using a special type of thesis called an enthymeme.
Thesis and Topic Sentences as Reasons
In an argumentative speech or essay, a thesis should present the writer's claim or position on a topic or issue. For example, if asked if they believe shoppers should be responsible for the environmental impact of the things they buy, a writer might answer one of two ways. First, however, a writer will need to investigate the issue, read about the environmental impacts of various industries or specific products, look through their own inventories, identify experts, and talk to or read what have to say about the issue. After investigating, they will come to a conclusion based on their new knowledge, and they might say that shoppers are not responsible for the environmental impact of the things they buy, or they might say that shoppers are responsible for the environmental impact of the things they buy. Either one of those two statements could be a thesis. In order to write a speech or essay about the topic, however, they will also need to explain their reasons for coming to that conclusion, and those reasons will appear in an essay or speech as topic sentences.
The following is a minimal outline that demonstrates how a thesis and topic sentences stated as reasons might appear in an essay or speech outline. Because the thesis does not include a reason for the claim, the topic sentences should be stated as reasons for the claim.
Thesis: Shoppers are responsible for the environmental impact of the products they buy.
Topic Sentence One: Shoppers are ultimately responsible for the environmental impact of the things they buy because of the impact of capitalism, supply and demand.
Topic Sentence Two: Because of the global economy, and an unknowing of regional environmental issues, shoppers are responsible for the environmental impact of the things they buy.
Topic Sentence Three: Shoppers are responsible for the environmental impact of the things they buy because only shoppers can control their individual conspicuous consumption.
Enthymeme and Examples or Categorical Topic Sentences
An enthymeme is a statement of a writer's claim or position on an issue that includes the reason why the writer came to that conclusion about the issue at hand. For example, a writer might generate a rough draft or working thesis in which they state, "Shoppers should look into the environmental practices of the companies they buy from." In order to revise and elevate that claim, the writer might later state, "Responsible shoppers investigate the source of their products before buying in order to avoid rewarding environmentally destructive practices." The revised claim includes the writer's reason for making their claim. Because the enthymeme includes a reason for the claim, the topic sentences need not be stated as reasons. Instead, the writer might use the topic sentences to break their paragraphs into examples or types of destructive practices to be avoided or ways to do so.
The following is a very minimal outline of an enthymeme and its topic sentences. Notice that the topic sentences introduce examples or categories instead of listing additional reasons. The main reason "trickles down" to the paragraphs from the enthymeme.
Enthymeme: Responsible shoppers investigate the source of their products before buying in order to avoid rewarding environmentally destructive practices.
Topic Sentence One: Palo Santo wood, sage, turquoise, and other natural or unprocessed materials are one example of a type of resource that is endangered because of irresponsible sourcing and shopping practices.
Topic Sentence Two: The fast fashion industry is also well known for its negative impact on the environment.
Topic Sentence Three: The most often cited industry for its negative impact on the environment is, unfortunately, something everyone buys: food.
Which of the two minimal outline above are more interesting to you? Personally, I like the second a bit better and would opt to use it as my structure if I were assigned this writing prompt. However, the first leaves room for exploring some economic philosophies, and that would be interesting reading, as well. It's hard to decide!
No matter which type of claim a writer makes, thesis or enthymeme, the reasons for why they came to their conclusion about the topic are an essential part of making a complete argument. When using a thesis, topic sentences become reasons why the writer came to the conclusion. When using an enthymeme, the reason becomes part of the claim statement.
Want to read more about argumentation and argumentative essays and speeches? Try
Writing an Argumentative Essay: Basic Terminology
Writing for an Intended Audience
The Difference Between Persuasion and Argumentation
Copyright Amy Lynn Hess. Please contact the author for permission to republish.