FALLIBLE FOX

Evaluating Arguments (Arguments & Claims Part 4)

​

What makes an argument good or bad? This gets hard when we're dealing with arguments that we find out in the messy real world. There's a lot to bring into our thinking here, but we'll keep it to a simple framework for this basic introduction. A nice first step when you wish to evaluate an argument is to first prepare it by putting it into standard form. Standard form is a method of presenting arguments in an orderly way, with premises clearly and concisely listed and labelled first followed by the conclusion. The video linked here provides a brief summary of how to set up an argument in standard form.

​

Once you have an argument clearly laid out, whether that's in standard form or using your own personal method, it's time to consider what aspects of the argument need evaluating. There are three things to consider in evaluating the merits of an argument (Bassham et al., 2019). 

​​

1. Are the premises true?

2. Does the conclusion follow from the premises?

3. Does the argument meet other relevant standards for critical thinking?

​

First, an argument with demonstrably false premises is one that you can discard immediately. Unfortunately, in practice, it's often hard to differentiate truth from falsity. Even for topics that interest us, we're generally not experts. For example, you may feel like you can follow the thread in a podcast interview on the good and bad science surrounding COVID-19 treatments, but do you have any capacity to judge whether the interviewee's claims are true? Probably not. Many people have recently accepted false claims about the efficacy of a drug called Ivermectin as a COVID-19 treatment, in part, because of poor capacity to judge the veracity of those claims. The first thing we we often need to do, then, is to think about how much we really know about the subjects that are relevant to the argument at hand. For mental tools that can help you consider your own relative expertise, visit the first chapter of the metacognition module. 

​

There are also things that can distract us from appropriately assessing the truth of a premise. For example, we can be misled by what we want to be true. If it feels morally righteous to accept a premise as true—perhaps, for instance, it aligns with your politics—it's easy to mistakenly accept it and move on. On the other hand, if we feel uncomfortable accepting a premise, we may jump more swiftly to viewing it as false. For example, we may feel that accepting the claim could lead to social rejection among our peers or punishment from authorities. This discomfort or fear, is not a rational reason to dismiss a claim or to label it as false. For mental tools that can help you consider whether you're being led astray by cognitive biases, emotions, or social expectations, you can start by visit the the metacognition module.

 

Additionally, if we believe a conclusion to be true, it can often be easy to work backwards and accept reasons (premises) an author offers in support of that conclusion. That too would be a mistake. The sense we have that a conclusion is true says nothing about the truth of premises and it says nothing about whether an author or speaker is supporting said conclusion with good reasons and reasoning. Remember, the premises are intended to be the reason to accept the conclusion—not the other way around! That can be hard in practice.

​

Based on the previous paragraphs, I hope you can see significant relevance of our capacity to think about our own thinking. Revisiting the metacognition module will therefore help to support (a) whether you have enough knowledge to judge the veracity of premises and (b) whether you're ready to work around your biases when judging premises.

 

We'll consider the evaluation of truth claims more fully in the next section of the Arguments and Truth Claims module.

​

The second thing to do when evaluating the merits of an argument, is to assess whether the conclusion follows from the premises. For an argument to be a good one, we need more than true premises—those premises must offer good reason(s) to accept the conclusion. For that, the premises and conclusions need to be connected in a logical way. That is, the premises should work together to support (as in the case of inductive arguments; see previous chapter on Kinds of Arguments) or prove (for deductive arguments) the conclusion. We can easily be misled if we're fixated solely on perceived truth of premises and/or conclusion. This is part of what makes the following argument so tricky:

​

All living things need water. (premise 1)

Roses need water. (premise 2)

Therefore, roses are living things. (conclusion)

​

Because we know that both the premises and the conclusion are true in this argument, it's easy to be tricked into thinking that the conclusion follows from the premises. However, as discussed in the previous chapter, that judgment would be a mistake. The truth of premises is an entirely different concern from the connection between the premises and the conclusion. We can see this more clearly in the more obvious but logically equivalent example below:

 

All living things need water. (premise 1)

Beer needs water. (premise 2)

Therefore, beer is a living thing. (conclusion)

 

This way of thinking gets us into trouble because there are many things we believe to be true that may not be. People who believe the Earth is flat, for example, could fall prey to poor logic when a premise is true and a conclusion is believed to be true:

​

The earth looks flat to me. (premise)

Therefore, the earth must be flat. (conclusion)

​

The premise may well be true—because it's so huge, the earth does appear to be flat to the naked eye. For a flat earther, who may be biased toward believing that conclusion, it can be easy to accept the premise as reasonable support. Everything there may feel right. This, of course, neglects a key piece—the premise does not actually provide any support at all for the conclusion! We know that a person's perception about the shape of the earth is deceiving. It is simply not a reasonable way to study the shape of the earth—it doesn't offer any good evidence at all about its shape. This is why we need science, ,not just our own faulty perception and fallible minds, to help us understand the world around us. Once again, we can move the logic over to another domain to see the mistake in reasoning:

​

I don't see any molecules when I look at water. (premise)

Therefore, there must not be any molecules in water. (conclusion) 

​

The ​earth is too big and molecules are too small—under everyday circumstances, our eyes don't help use to draw conclusions about these matters.

​

But we don't reason poorly about the links between premises and conclusions because of prior beliefs alone. Often we just don't have the mental tools to see when one statement doesn't actually provide support for another. To better vet arguments for poor linkages between premises and conclusions, it's useful to understand formal and informal logical fallacies. Logical fallacies reflect different types of errors in the association between premises and conclusion. Knowing at least a few common ones, you'll be better able to put a label on many errors in logic that you might otherwise miss.

​

Formal fallacies occur when deductive reasoning goes awry—that is, when a deductive argument is invalid. One common example is called affirming the consequent, which occurs when the truth of a consequent is said to prove its antecedent. It takes the following form:

​

If A then B.

B.

Therefore, A

​

An example is as follows:

​

If Kara is cooking her kids breakfast, then she's in her kitchen.

Kara is in her kitchen.

Therefore, Kara is cooking breakfast.

​

The error here is that the consequent—Kara's in her Kitchen—does not necessarily mean that Kara is cooking breakfast. While the logic clearly stipulates that Kara must be in her kitchen if she's cooking breakfast, the converse is not true. If Kara's in her kitchen, she could be doing any number of things: cooking dinner; eating a snack; doing her taxes; arguing with her husband, etc. As such the argument is invalid (see Kinds of Arguments chapter). The following, by contrast, works just fine (it's valid):

 

If Kara is cooking her kids breakfast, then she's in her kitchen.

Kara is cooking her kids breakfast.

Therefore, Kara is cooking breakfast.

​

A look at additional formal fallacies can be found here. We'll explore informal fallacies in an upcoming section. These sorts of fallacies pertain to inductive arguments, are common in everyday reasoning, and students often find more interesting.

​

So, to review what we have so far, a good argument has all true premises and a conclusion that follows logically from those premises. One final piece to consider in evaluating arguments is whether the argument meets relevant standards for critical thinking (see Critical Thinking Primer). The two previous criteria are about accuracy (are the premises true?) and logical correctness (does the conclusion follow from premises?). Accuracy and logical correctness are essential critical thinking standards in evaluating any argument, but it's also important to consider other standards noted below.

​

• Clarity. Don't be fooled by unclear writing or speech. If you encounter an argument online the seems obscure or muddy, the author might be offering you something profound but they could also be feeding you complete nonsense. If, no matter how hard you try, you can't make sense of it, move on. Don't accept premises, conclusions, or links between the two because you've assumed the author is saying something insightful that's beyond your intellectual reach. If the author or speaker's goal is to make an argument, they should be aiming to be as clear as possible. If they're not being clear, perhaps they're not experienced writers, speakers, or arguers. Alternatively, they could have other goals—to impress, to obscure the truth, to appear knowledgeable, etc. Finally, it's possible that you're simply not be part of the intended audience (they may be intending to reach other scientists or philosophers only, for example). In any case, if you don't understand, you have no reason to accept the argument. But perhaps, you have little reason to assume they're wrong either! Remain uncertain. Move on.

​

• Precision. You'll sometimes hear an argument with a complex concept, such as love, violence, or bias, at its core. Ask whether the author is being precise about what they mean by the target concept and how they're using it. Sometimes, by being imprecise, an author can end up fooling the reader with fallacious arguments and irrelevant examples. Precision is particularly important in works that deal with relatively new, ambiguous, or contentious concepts, like microaggressions, and concepts that are defined in subtly different ways by different people, such as addiction, bullying, or genocide.

​

• Relevance. Online writing, such as that found in social media and blog posts, is often done quickly and can sometimes be a mess. This create's clarity issues, but it can also be easy for authors to bring up irrelevances that, because our reading is often done quickly, can seem relevant at first glance. Sometimes this is accidental and sometimes it's done on purpose, such as to distract readers from a weak argument. Consider whether an author or speaker raises irrelevant points and why they may have done so.

​

• Completeness. An author might base a premise on a bit of seemingly good evidence, like a particular research study. The author may seem quite confident in the conclusions they draw. However, we should be wary of claims made based on very little evidence with no reference to the broader literature from which that research comes. What's the consensus in the field? Have independent researchers replicated the findings of the study? Would it be just as easy for the author to find a study that contradicts the claim? If it seems like the author has only done some cursory or surface level research—even if it seems they've crafted a well-written piece—there could be a lot more relevant  information that they haven't considered, thus rendering their argument incomplete.

​

• Fairness. There is a great deal of political polarization in the media landscape, with outlets all over the political spectrum—from Vox on the left to Fox News on the right—seeking to capture the interest of their respective audiences. Even if you agree with the claims, consider whether the source is fairly considering the relevant perspectives (and not inappropriately balancing things with the wrong perspectives; e.g., non-experts, public opinion, etc), considering the evidence in an unbiased manner, and not judging individuals by stereotypes attributed to the groups or organizations to which they belong. Vested interests, political bias, and lazy thinking are rampant and can result in unfair portrayals of people, science, and ideas.

​

Note that the next two sections will take a deeper look at truth claims and logical fallacies. These two sections will support the first two criteria for evaluating arguments: the truth of premises and the logical relationship between the premises and conclusion. They are, however, considered separately from this overview of evaluating arguments because each is a topic with wide-ranging relevance even beyond the argument context. For instance, evaluating truth claims is important in effective assessment of unsupported assertions, reports, and explanations. Understanding logical fallacies is clearly important to evaluating others' arguments, but also to cleaning up our own thought processes.