Now that you are in college, your instructors will no longer be satisfied by simple reflection papers in which you state your opinion. Instead, your college professors will ask you to produce organized, focused, and rhetorically effective, academic argumentative essays. Writing such an essay can be challenging, especially if you have never done it before, but it all starts with one building block, the cornerstone or foundation upon which you will build the rest of your paper. What is that building block? You guessed it; it's the argumentative thesis statement.
Although the phrase "argumentative thesis statement" sounds a bit frightening, you don't have to be scared. A thesis statement is actually just a one-sentence summary of the main point of your paper, and most instructors require it because it can actually help you write your paper, not to mention making the final product a whole lot easier to follow. The thesis statement begins with a topic--what you are writing about--and an arguable claim, or the argument you are trying to make. If you were trying to argue against required gym credits in college, for example, your thesis might start off a little like this: "Gym classes are an unnecessary part of a college education."
In this example, the topic is "gym classes"--after all, this is what you are writing about--and the claim is that they "are an unnecessary part of a college education." Now, before you start thinking that this argumentative thesis thing is actually very easy, so easy that your 10-year-old brother could do it, and scamper off to pound out your paper in 15 minutes, take a moment to consider the idea of "argumentative claim" again. The claim in the example above is argumentative because there is more than one acceptable answer.
In other words, people could argue this claim--they could stage a debate, and it would be interesting not ridiculous. Some people might say that we need gym classes because they help students develop healthy exercise habits; some may say they are a waste of money and college students are adults responsible for their own health; still others might say gym classes are unnecessary the way they are currently taught, and if we got better teachers, they would be an important part of the college experience.
Now, think about whether the same kind of argument could be applied if your claim was that the Civil War was fought from 1861-1865, or that the sky is blue, or that taking candy from a baby is unethical. Probably not much to argue, right? And this is where the difficulty of the argumentative thesis comes in--you have to have a real, debatable claim to write a good argumentative thesis, something people could honestly debate over.
This means you want to stay away from writing arguments about facts--unless your argument is that some previously accepted fact is wrong--and ethical issues that are so obvious that they would be difficult to debate. That doesn't mean you can't write ethical arguments, since some of the best debates involve them, but you should make sure the issue is actually arguable. For example, "Murder is wrong," is not exactly arguable, but "Abortion is murder" and "Capital punishment is murder" are.
Finally, you need one more component after your argumentative claim to make an argumentative thesis statement: support. Perhaps you have heard of this part of the thesis referred to as the "because" statement. The support section of your argumentative thesis is where you list why you believe your claim to be true. This section both helps you build your credibility (what we stodgy, professorly types like to call your appeal to ethos) in the first paragraph of your paper and set up an easy-to-follow organization, as you will (or at least should) use your thesis statement as an outline of your paper's organization.
For example, if your thesis statement is "Gym classes are an unnecessary part of a college education because they cover material already learned in most high schools and take time away from academic study," the "support" section of your thesis would begin with the word "because." By looking at this thesis statement, the reader would have a good idea of not only what arguments will be made in the paper, but in what order they will be made--you will discuss the high school argument before the academic study one. Thus, your reader is familiar with your organization, and there are no surprises, which means she is going to find it easier to understand and, hopefully, accept.
An argumentative thesis statement, then, is composed of three parts--a topic, an arguable claim, and a support section. While it's not so easy that your 10-year-old brother writes these things for fun, it's also not too difficult, and once you have one in place, you'll probably find the rest of the writing process much easier--just don't forget to change your thesis if you change your argument halfway through your paper!