Evaluating an Argument

Logical Arguments

Anything you read that includes an attempt to persuade you to think a certain way is likely to include logical argument as part of that persuasion.  As you view the rest of this section, think about the relationship of premises and conclusions as they align with main ideas and supporting details.

Argumentation Key Terms:

• Claim: a statement or opinion that is either true or false

• Argument: a claim supported by premises

• Conclusion: the main claim in an argument

• Premises: claims that support and argument’s conclusion

A claim is an assertion about the truth, existence, or value of something that is either true or false. Claims are also called statements or propositions.

When supported by premises, a claim becomes a conclusion. For example:

• This class is easy.

• The Detroit Lions have the potential to make the NFL playoffs.

• This chemical structure is unstable.

• Democratic socialism is superior to a pure democracy.

An argument is an assertion that contains both a conclusion and premises. It is a statement of fact or opinion that is based on evidence. Keep in mind that not all statements are arguments, and some statements may contain multiple arguments.

A conclusion is the main claim of an argument that is supported by a premise. It is the logical result of the relationship between the premises. Identifying the conclusion is the first step in understanding the argument.

But, how do you identify the conclusion? Follow these steps:

1. Ask, “Is the statement the main point, or is it a claim given to support another statement in the argument?

2. Identify the indicator word that often precedes the conclusion, such as:

• Therefore

• Thus

• As a result

• That’s why

• Consequently

• So

• This Means

• This shows

• It follows that

• This suggests

• Hence

• Accordingly

A premise is a reason offered as support, or evidence, for another claim. It is often indicated by these words:

• Because

• For

• As

• Since

• In as much as

• As shown by

• Given that

• As indicated by

• The reason is that

Consider the following statement: Today’s freshmen cannot write very well. Joe is a freshman, so he must be a poor writer. The premises and conclusion are identified as follows:

• Premise: Today’s freshmen cannot write very well

• Premise: Joe is a freshman,

• Conclusion: So, he must be a poor writer.

Identify Support for Author’s Claims (Rhetorical Appeals)

Writers are generally most successful with their audiences when they can skillfully and appropriately balance the three core types of arguments called rhetorical appeals. These appeals are referred to by their Greek names: “logos” (the appeal to logic), “pathos” (the appeal to emotion), and “ethos” (the appeal to authority and ethics).

Logical Appeals (Logos)

Authors using logic to support their claims will include a combination of different types of evidence. These include the following:

• Established facts

• Case studies

• Statistics

• Experiments

• Analogies and logical reasoning

• Citation of recognized experts on the issue

Emotional Appeals (Pathos)

Authors using emotion to support their claims again have a deep well of options to do so. These include the following:

• Personal anecdotes

• Narratives

• Impact studies

• Testimony of those involved first-hand on the issue

Authoritative Appeals (Ethos)

Authors using authority to support their claims can also draw from a variety of techniques. These include the following:

• Personal anecdotes

• Illustration of deep knowledge on the issue

• Citation of recognized experts on the issue

• Testimony of those involved first-hand on the issue 

Most texts rely on one of the three as the primary method of support, but may also draw upon one or two others at the same time.

Point, Illustration, Explanation

Many authors use the “PIE” format to structure their writing. PIE = point, illustration, explanation. The point furthers a thesis or claim. The illustration provides support for the point, and the explanation tells the audience why the evidence provided furthers the point and/or the thesis.

Review the example below from Tareq Hajj, a student at Radford, who is making an argument for the "+/-" grading system:

Without the A+, students with high grades in the class would be less motivated to work even harder in order to increase their grades.  Professor Fesheraki writes, “Students have less incentive to try” (2).  Therefore, not providing the most motivated students with additional motivation of a higher grade is inequitable.

Let's breakdown the example according to the PIE method:

• Point: “Without the A+, students with high grades in the class would be less motivated to work even harder in order to increase their grades.”

• Illustration: “Students have less incentive to try” (2).

• Explanation: “not providing [the most motivated students] with additional motivation of a higher grade is inequitable.”

Types of Evidence

Any text should provide illustrations for each of its points, but it is especially important to provide reliable evidence in an academic argument. This evidence can be based on primary source material or data (the author’s own experience and/or interviews, surveys, polls, experiments, that they may have created and administered). Evidence can also stem from secondary source material or data (books, journals, newspapers, magazines, websites or surveys, experiments, statistics, polls, and other data collected by others).

Let’s say, for example, that you are reading an argument that college instructors should let students use cell phones in class. Primary source material might include a survey the author administered that asks students if policies forbidding cell phone usage actually stop them from using their phones in class. Secondary sources might include articles about the issue from Faculty Focus or The Chronicle of Higher Education.

Recognize Propaganda Techniques & Logical Fallacies

Propaganda is a way to deliver a message that appeals to the emotions instead of presenting solid evidence to support a point. It is used by advertisers, salespeople, and politicians who may lack adequate facts to persuade people to support their point of view. Governments may use propaganda to rally support and influence people for a specific agenda, such as war. Part of being a critical reader is the ability to recognize these propaganda techniques.

These misapplications of logic—known as logical fallacies—occur frequently in reading and in daily life. Read through the list below to explore some of the most common ones.

• Hasty generalization: argues from limited examples or a special case to a general rule.

  • Argument: Every person I’ve met has ten fingers; therefore, all people have ten fingers.

  • Problem: Those who have been met are not representative of the entire population.

• Making the argument personal (ad hominem): attacking or discrediting the opposition’s character.

  • Argument: What do you know about the United States? You aren’t even a citizen.

  • Problem: personal argument against an opponent, instead of against the opponent’s argument.

• Red herring: intentionally or unintentionally misleading or distracting from the actual issue.

  • Argument: I think that we should make the academic requirements stricter for students. I recommend that you support this because we are in a budget crisis, and we do not want our salaries affected.

  • Problem: Here the second sentence, though used to support the first, does not address the topic of the first sentence; instead it switches the focus to a quite different topic.

• Fallacy of false cause (non sequitur): incorrectly assumes one thing is the cause of another. Non Sequitur is Latin for “It does not follow.”

  • Argument: I hear the rain falling outside my window; therefore, the sun is not shining.

  • Problem: The conclusion is false because the sun can shine while it is raining.

• If it comes before, it is the cause: believing that the order of events implies a causal relation.

  • Argument: It rained just before the car died. The rain caused the car to break down.

  • Problem: There may be no connection between the two events.

• Two events co-occurring is not causation (cum hoc ergo propter hoc): believing that two events happening at the same time implies a causal relation.

  • Argument: More cows die in the summer. More ice cream is consumed in summer months. Therefore, the consumption of ice cream in the summer is killing cows.

  • Problem: No premise suggests that ice cream consumption is causing the deaths. The deaths and consumption could be unrelated, or something else could be causing both, such as summer heat.

• Straw man: creates the illusion of having refuted a proposition by replacing it with a superficially similar proposition (the “straw man”) and refuting it without ever actually refuting the original.

  • Argument: Person A: Sunny days are good. Person B: If all days were sunny, we’d never have rain, and without rain, we’d have famine and death. Therefore, you are wrong.

  • Problem: B has misrepresented A’s claim by falsely suggesting that A claimed that only sunny days are good, and then B refuted the misrepresented version of the claim, rather than refuting A’s original assertion.

• The false dilemma: the listener is forced to make a choice between two things, which are not really related or relevant.

  • Argument: If you are not with us, you are against us.

  • Problem: The presentation of a false choice often reflects a deliberate attempt to eliminate any middle ground.

For more explanation of logical fallacies and to learn about more of them, please view the videos to the right.

When you evaluate an argument for logical fallacies, you consider what elements of the argument, if any, would cause an audience to believe that the argument is illogical or inappropriately manipulative. If you determine that these fallacies have been committed, you should question the credibility of the author and the legitimacy of the argument.