Overview
The thesis, or claim, is the guiding idea of an argument.  It is, in short, the claim that you will be supporting with reasoning and research.

Formulating a Position
Your position, roughly stated, is your overall stance on the issue, your broad answer to the question.  "Same sex couples should be allowed to marry," for example, states a general opinion on a topic.

Your position will most likely be the actual answer to your research question.  However, some ideas to bring you to your position are:

• What positions have you encountered in your research?
• What seems to be strongest and weakest in each stance?  How might the weaker positions be made stronger?
• Is there a position that you're not seeing that seems obvious to you?
• Which evidence has really impressed you?  Which seems strongest?  Why?

Your position must meet two basic criteria:

• It must be supportable.  Now, by this I don't mean "must be able to be proven beyond a shadow of a doubt."  Few positions can be.  However, you must be able to present evidence acceptable to the context (in this case, an academic research paper) and audience that will support your position.  In that line, positions to avoid are:
  • Tomato and lima bean positions.  I take this term from an old family argument: I love tomatoes and hate lima beans, and my brother loves lima beans and hates tomatoes.  Despite endless arguments when we were five, arguing matters that ultimately come down to questions of personal taste is futile.  For example, to argue that horror is inherently inferior as a genre would be futile, because ultimately, this comes down to what kinds of stories an individual likes and dislikes.
  • Questions of morality.  Now, I'm not saying these aren't worthy discussions to have.  However, outside of a religion or ethics class, arguing the morality or immorality of something becomes a very sticky proposition.  The reasons are complex, but ultimately they come down to audience: by the time you get an audience who shares enough of your assumptions about what is and is not moral, or about what we should base our moral codes on, they will most likely agree with your position on the topic anyway, in which case, why bother making the argument?  This is not to say that morality cannot be part of a larger argument about a law or issue, but basing your argument entirely on morality is a difficult prospect at best.
• Someone has to care.  Now, again, chances are you can find a community that cares about almost anything.  Certainly I've had passionate debates about the relative strength of various costumed superheroes.  However, there are positions that you can present a detailed, careful argument about, only to be met with "...And?"  What's worth remembering here is that your audience is an academic one, and therefore your position must be something academia would care about.  Academia would be interested in an argument that Superman as a cultural icon represents our national image as world leaders and fixers of international problems, and that Batman as a cultural icon represents our belief in the power of the individual over the power of the system.  They would be less interested in an argument about who would win in a fight. (Even though Batman would).

Formulating a Thesis
The thesis is a more refined statement of your position specifically developed for your paper.  A thesis will generally accomplish several things:

• It asserts a specific position about the topic.
• It conveys the reason for asserting and defending that position (in other words, why are you writing this?)
• It sometimes provides a concise preview of the reasons that support your position.

Notice that I do not use the term "thesis statement."  A thesis may be more than one sentence long.  In fact, for a paper as long as this one, it will almost have to be.

So, going back to our sentence above, "Same sex couples should be allowed to marry."  Now, this does assert a specific position.  However, it's not very elegant, nor does it do much more than assert a position.

The book from which I took this example (the one I didn't make you buy) revises this statement into "Everyone couple who wishes to commit to each other in marriage should have the right to do so, regardless of sexual preference" (225).  What does this statement do that "Same-sex couples should be allowed to marry" does not?  Let's break it down.

First, consider the audience at which this argument is aimed.  Mostly likely, it is going to be aimed at people who are at the very least ambivalent, and perhaps mildly opposed, to the marriage of same-sex couples. The initial position statement begins with "Same-sex couples."  A reader opposed to same-sex marriages is already anticipating a "should or should not" statement, and is preparing to react accordingly.

The revised thesis begins with the statement that "Every couple who wishes to commit to each other in marriage should have the right to do so, regardless of sexual preference."

• We begin with "every couple" - the type of couple is not defined, thus avoiding the defensive reaction.
• "who wishes to commit to each other in marriage" appeals to fairly traditional values, which are likely to be held by the audience.
• "should have the right to do so" - "right" is a very powerful word in Western culture.
• And not until "regardless of sexual preference" do we arrive at the issue of same-sex couples, and even then, it is stated to avoid either "same-sex" or "gay and lesbian."

Now, clearly on a macro-level, the reader will know the topic before getting to the thesis, but the breakdown does help explain why the second thesis is better.

The book suggests a further revision of "Everyone, gay and straight, will benefit from extending the basic human right of marriage to all couples, regardless of sexual orientation."  This reintroduces the problem of fore fronting sexual orientation; however, it also provides a preview of what the paper will argue.  Based on this thesis, we can expect not just an argument in favor of same-sex marriage, but an argument that allowing same-sex marriage will benefit society in general.

A more expanded thesis might even go so far as to say:

"Every couple who wishes to commit to each other in marriage should have the right to do so, regardless of sexual preference.  Extending this basic human right to all couples would greatly benefit society by reinforcing marriage as an institution, providing stability to non-traditional families, regularizing health care benefits across states and companies, and eliminating the need for anti-discrimination legislation.