Devoted to the Propagation and Defense of New Testament Christianity
VOLUME 20
May 23, 1968
NUMBER 4, PAGE 8b

Post Hoc Ergo Proter Hoc

H. L. Bruce

There is a vocabulary to logic that many of us know but little about. Yet we try and reason with each other and frequently declare something to be illogical. When we proclaim something to be illogical and are asked "What's illogical about it?" we are sometimes without technical vocabulary and thought for the forthcoming exposition. One of the fallacies in illogical reasoning is a science of thought known as post hoc ergo proter hoc.

Post hoc ergo proter hoc is a method of reasoning which stems out of an abuse of cause and effect. Certainly every effect must be preceded by its cause. However it is a mistake to conclude that because some action preceded a certain effect cause.

To illustrate this fallacy, let's say a man (as the Honorable Herbert C. Hoover was) is elected president. The very next year our economy collapses. Is it logical for us to conclude that just because he was elected that he was the cause of the collapse? Again let's suppose that three soldiers use the same razor to shave. Later in the day the last man to use the razor is shot and killed. Is it logical for us to conclude that his being the third one to shave with the razor that morning had anything to do with his being killed?

The church and her members haven't altogether escaped this fallacy in reasoning. Several years ago a certain young man who was not a Christian was attending services regularly with an East Texas church. He came to the local preacher's attention and the preacher was interested in encouraging the young man to obey the gospel. Finally when time passed and the young man was still in alienation the preacher talked with this young man. The young man was sensitive, got his feelings hurt, resented the preacher's efforts and never returned. Some reasoned that the preacher trying to convert the young man caused him to be lost eternally.

I have several good preacher friends who fear the Lord and are conscientious about conditions which exist in congregations where they preach. When members dance, drink, curse and are otherwise disorderly they speak out. They condemn sin and stand firm against corruption within the congregation where they preach.

Needless to say those who don't want to do right resent their actions. When those who drink, dance, swear, lie, cheat, steal, etc. don't want to correct their lives they make a counterattack upon the preacher. These conscientious, God-fearing preachers have had to deal with such conditions to such extent that some reason that where they go they cause trouble. Right thinking people can see the fallacy in such reasoning as well as the lack of fairness involved.

If you will notice all of these illustrations they have one thing in common. They illustrate an unfair and illogical kind of thinking. In each case there was the instance of thought which reasoned that because something preceded an event it caused it. The name of the fallacious logic is post hoc ergo proter hoc; and many have been its victims.

Mt. Pleasant, Texas