Refuting Fallacies on Appeal – One Way v. Only Way

This post begins a series on logical fallacies that I have run across in handling South Carolina appeals. My thanks to D.Q. McInerny and his book, Being Logical, for naming these fallacies and for its clear examples.

A statute that I dealt with a while back applied when a child is harmed.  Counsel for one of the parents cited cases applying the statute to parental beatings, arguing that the statute did not apply because the parent did not beat the child. Problem was that the statute did not limit who it applied to or the type of harm required.

This is a fallacy known as “denying the antecedent.” The argument goes like this — if a parent beats the child, the statute is satisfied; the parent did not beat the child; thus the statute is not satisfied. Yet this confuses one way to satisfy the statute with the only way to satisfy it.

McInterny’s example makes the point clearer: If Louise is running, then she is moving; Louise is not running, thus she is not moving. But there are, of course, other ways to move besides running, just as there are other ways to harm a child besides a parental beating.

The flip side of denying the antecedent is “affirming the consequent.” To reuse McInerny’s example, the argument goes: If Louise is running, she is moving; she is moving, therefore she is running. Again, the problem is that running is not the only way to move. The same confusion exists between one way to do something with the only way to do it.

Has anyone else run across this fallacy? Please leave me a reply or reach me  here.



Leave a Reply