Reasons to Believe

Logic 101, Part 9 (of 12)

When I was growing up my mother used to say that I liked to argue. In subtle ways my parents encouraged me to be an independent thinker, ready to back up my strong opinions. An argument develops when a person attempts to support an opinion with facts, evidence, or reasons. While my parents did not receive much formal education (forced to drop out of school to work during the Great Depression), they valued learning and appreciated vigorous intellectual debate over important issues.

Unfortunately, when you strongly disagree with someone over a critical issue it is easy to lose sight of your opponent's logical argument and instead attack or impugn their character. This proclivity illustrates humankind's flaws of both mind and moral fiber.

Logical Fallacy

In logic, assaulting an opponent's character is considered an informal fallacy known as the ad hominem or "attack against the man." If a person's character is not the logical issue at hand, then any appeal to character-related issues is logically irrelevant. Even morally flawed people can present cogent logical arguments.

The ad hominem fallacy comes in three identifiable varieties:

  1. Abusive: directly denouncing character (old-fashioned name-calling)
  2. Circumstantial: raising special circumstances in an attempt to discredit a person's motives (also known as "poisoning the well")
  3. Tu quoque: accusing the other person of hypocrisy as an attempt to avoid personal criticism

There are certainly times when criticism of character is logically legitimate, that is, when the character of the person is the logical issue at hand. For example, jurors in a trial need to know if a witness has been convicted of perjury in the past. In cases such as that, character issues impact the witness's believability.

Avoiding the Ad Hominem Fallacy

As forgiven sinners, Christians are certainly not immune to engaging in "name-calling" or impugning the character (or motives) of others. However, to steer clear of this fallacious practice during a rigorous debate involves intellectual concentration and moral discipline. When critiquing the position of an opponent, stay focused on the central argument at hand. Realize that uncovering the truth of an issue is itself a noble task. And arguing cogently and fairly is certainly much more important that winning an argument by appealing to illegitimate and/or dishonest tactics.

If you are the victim of an ad hominem attack while engaged in a debate, resist the temptation to respond in kind. Instead, clearly identify the irrelevant attack on the part of your challenger. Then you can refocus the discussion by getting the discourse back to the logically relevant issue.

Often times those listening to the discussion will appreciate the care and fairness you have exhibited and will be more open to your viewpoint. Even your opponent may be impacted positively by your show of intellectual integrity.

Remember, attitude and demeanor may carry as much weight toward ultimate persuasion as do the arguments themselves. Persuading my parents definitely depended upon exhibiting a proper attitude.

Check in next week for more about the important topic of critical thinking.

For more about the importance of logic and critical thinking, see my book A World of Difference: Putting Christian Truth-Claims to the Worldview Test. For a great handbook in dealing with logical fallacies, see Attacking Faulty Reasoning: A Practical Guide to Fallacy-Free Arguments by T. Edward Damer.


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Subjects: Logic

Kenneth R. Samples

I believe deeply that “all truth is God’s truth.” As an RTB scholar I have a great passion to help people understand and see the truth and relevance of Christianity’s truth-claims. Read more about Kenneth Samples.