How to Spot and Counter the Ambiguity Fallacy

In our world of argumentation and reasoning, clarity and precision are of vital importance. However, many times, apologists use ambiguous terms to argue points. To do this, they often employ the ambiguity fallacy. Ambiguity fallacies exploit the vagueness or equivocal nature of language, resulting in flawed reasoning and invalid inferences.

Here’s an example of this fallacy that a pro-choice person might make: “Abortion is a personal choice. No one should be able to dictate what a woman can or can’t do with her own body. It’s about bodily autonomy and reproductive freedom.”

In this argument, the pro-choice advocate is using the phrase “her own body” ambiguously. The ambiguity lies in whether “her own body” refers solely to the woman’s body or includes the unborn child as well.

If “her own body” is taken to mean only the woman’s body, excluding the baby, then the argument appeals to the woman’s right to make decisions about her own physical self. However, if “her own body” is interpreted as encompassing the baby as well, then the argument becomes more problematic, as now you are advocating for killing a separate human deserving rights and protections.

Using words differently in different contexts is something that all languages do. As the old joke goes, “Three guys walked into a bar. The fourth one ducked and saved himself a headache.” But this ambiguity often gets weaponized in Protestant apologetics. For example, one Protestant Apologist makes this fallacious argument when he argues that Paul’s use of the words “suffer loss” in 1 Corinthians 3:15 can’t refer to purgatory because Paul used the same term one other time in another letter to mean a different thing.  Without more proof, this is an ambiguity fallacy, because Paul could be using the same term in two different ways.

Another would be assuming that because God is called a rock in other parts of the Bible, such as in 1 Corinthians 10:4, he must also be the rock in Matthew 16:18: “You are Peter, and on this rock I will build my Church.” However, this is also a fallacy, as the word could apply to different people in different contexts.

Just because a word means something in some context, it doesn’t follow that it means that in every context. We have to examine each situation discretely if we do not want to commit the ambiguity fallacy.

Want to know more? Order your copy of The Protestant Fallacies: Ten Anti-Catholic Arguments that Break the Laws of Logic today!