Assumptions

In most argumentative papers, it’s crucial to outline any crucial background assumptions that you will be holding/using throughout the paper so that you can clarify the thesis and narrow the scope of your paper.  Your thesis should tell you what background assumptions you need to make; not always explicitly, of course, but you can generally see what it might be plausible and helpful to assume for the sake of the argument once you’ve written the thesis (more on this below).

Why Do I need to State my Background Assumptions?

Before I provide advice about making assumptions, I should explain briefly why stating your assumptions explicitly is important.  There are at least two reasons you ought to clearly and explicitly state your background assumptions: first, outlining key assumptions that support your argument will help clarify the thesis.  Outlining your key assumptions provides the reader with some sense of what you are taking for granted and set the expectations for what you’re trying to argue for.  This is very helpful for the reader because it gives her a better sense of what claims you will and will not be providing an argument for.  Doing this helps further clarify the thesis and keep the reader focused on your main claims.

Second, no one expects you to argue for every claim you make, and making assumptions helps narrow the focus of your paper; this is important, especially given that you only have so much space to write.  You can’t defend every claim you make.  If you were to attempt to do that, you might need to write a book, or series of books, and such a project is certainly not expected of any term paper.  Luckily, you don’t need to defend every claim you make.  The background assumptions are used to narrow the focus of the paper to make defending your thesis manageable.  So, the main goals of providing your assumptions (as they become relevant, which is usually very early on in the paper) is to clarify the thesis and narrow the focus of the paper.

What Assumptions Should I Include?

But you need to choose your assumptions carefully.  Specifically, you need to choose assumptions that are both plausible and helpful.  But what do plausible and helpful background assumptions look like?  To clarify what I mean here and provide some more specific guidelines, it will be helpful to first cover what assumptions are bad, that is, those assumptions that are implausible and unhelpful.

There isn’t any hard and fast rule about what makes an assumption implausible, but one helpful way of checking the (im)plausibility of an assumption is to compare it to the (im)plausibility of the conclusion.  An assumption is implausible relative to the conclusion if it is more counterintuitive than the conclusion you are trying to reach.  I once had a student begin a paper with the assumption that all pregnancies are diseases, which was used as a part of the argument for the conclusion that clinicians have a professional obligation to provide abortion services.  In this case, it will strike many that the assumption used to reach the conclusion (i.e., all pregnancies are diseases) is more controversial than the conclusion itself (i.e., clinicians have a professional obligation to provide abortion services).  Arguments that rest on assumptions that are more controversial than the conclusion will not be helpful to build a persuasive case!  So, only make an assumption to help your main argument when it is not more implausible than the conclusion.

But an assumption can be unhelpful even if it is not more controversial than the conclusion; this can happen when you make a controversial assumption that none (or almost none) of your opponents will agree with.  For instance, if I’m writing a paper defending the moral permissibility of abortion, it’s unpersuasive to merely assume that the right to bodily autonomy outweighs another’s right to life.  Notice, this assumption is not implausible; it will strike many, perhaps even the pro-lifer, as having some plausibility.  It may very well be true!  Yet even though it is plausible, it is not helpful to advance the thesis that abortion is morally permissible.  The reason this assumption is unhelpful to reach the conclusion is that many people already deny the assumption.  In other words, there isn’t much shared ground between the one writing the paper and her opponent.  If someone already denies one of the assumptions, then making that assumption won’t help persuade the reader that disagrees with the author – in this case, a pro-lifer – of the conclusion (and, of course, similar points can be made of similar assumptions if made by pro-lifers).  So, only make an assumption to help your main argument when it provides some common ground between you and your opponent.

An assumption can be unhelpful in other ways, such as when it is unrelated to the topic at hand.  This might seem obvious, but I need to say this explicitly because some assumptions that might seem relevant aren’t.  To keep on the abortion debate, suppose that a pro-lifer, in her defense of the moral impermissibility of abortion, assumes that a fetus can feel pain around 20 weeks gestation.  Suppose, also, that she goes on to defend Marquis and argue that abortion is morally impermissible because the fetus has a future like ours.  Notice that, absent some explicit connection between these two sets of claims, the assumption is not relevant to reaching the conclusion in this particular case because it does not help advance the argument.  And we know that this assumption does not help advance the argument because the argument might work even if the assumption is false.  In other words, the author might have a good argument that abortion is impermissible even if fetuses cannot feel pain at 20 weeks gestation.  So, only make an assumption to help your main argument when your argument depends on that assumption being true.

There are other ways that assumptions are implausible or unhelpful, but I think the foregoing thoughts provide good insight to what a plausible and helpful assumption might look like.

A Rough Rule of Thumb

The previous section gives us the tools to develop a rough rule of thumb for determining what assumptions to include in the paper.  When determining what assumptions to include in the paper, ask yourselves the following questions about the assumption/claim you’re looking to include in the paper that correspond to the three ways that a paper might be implausible or unhelpful that I’ve sketched above:

(1)   Is the assumption/claim more implausible than the conclusion? 

(2)   Will most or all of my opponents automatically reject this assumption/claim? 

(3)   Will my argument work if this assumption/claim is false?

If your answer to all three questions is “no,” then you have a good candidate for an assumption that is both plausible and helpful for the paper.  I should emphasize that this is merely a rule of thumb; it is not a hard and fast formula.

Now that I’ve given you some examples of what assumptions not to include in your paper, I’ll provide an example of a plausible and helpful assumption that will give us one more helpful criterion for determining whether or not we should include the assumption in the paper.  Consider the following thesis:

Thesis 6: In this paper, I will argue against a common attitude towards sex that Benatar (2001) has called the Casual View of Sex, the view that sex is a pleasure that is morally like any other pleasure and is constrained only by the sorts of moral constraints that follow all other pleasure-seeking activities.  The Casual View, I will argue, is wrong because it cannot explain why sexual infidelity is a particularly heinous type of promise breaking.  It cannot explain why sexual infidelity is particularly heinous because, if sex is, morally, just like any other pleasure, then sexual infidelity is no morally worse than other, more mundane types of promise breaking.

Given this thesis, it would be both plausible and helpful to assume (stated explicitly early on in the paper) the following claim: sexual infidelity is morally impermissible.  Notice that this assumption meets the test that I sketched above. 

Is the assumption more implausible than the conclusion?  No.  The assumption is not more implausible than the conclusion that the casual view of sex is wrong because many people might think sexual infidelity is wrong regardless of whether they think that there is nothing morally wrong with casual sex.

Will most of the author’s opponents automatically reject this claim?  Probably not.  It seems plausible enough.

Will the author’s arguments work if this assumption – the claim that sexual infidelity is morally impermissible – is false?  No.  The author’s argument explicitly requires the claim that sexual infidelity is morally impermissible.  To put the same point another way, the authors basic argument structure is this:

If the Casual View of Sex is true, then sexual infidelity is just as morally bad as other types of promise breaking.  But sexual infidelity is morally worse than other types of promise breaking!  So, the causal view can’t be right.

Now imagine the assumption we made, that sexual infidelity is morally impermissible, is false.  If sexual infidelity is not morally impermissible, then it cannot be worse than other types of promise breaking.  But that’s exactly what is required by the argument! (“But sexual infidelity is morally worse than other types of promise breaking!”).  So, the argument cannot work without the assumption that we made.

Therefore, since the answer to all three questions is “no,” the assumption that sexual infidelity is morally impermissible is a good candidate for an assumption/claim to include in this paper.