It’s Good #FallacyFriday ! This one is a tough one, so follow closely. Every week, Oliver Diaz-Neda will post a logical fallacy and an example to help you all become better debaters, persuaders and rational thinkers. What is a logical fallacy? It is defined as – a flaw in the structure of an argument which renders the argument invalid.
Today’s fallacy

Affirming the Consequent

This fallacy is more complex than the name implies. Affirming the consequent fallacies occur when a debater structures their argument in the following way:

1. If X, then Y

2. Y.

3. Therefore, X

In this structure, it is asserted that the consequence (Y) is true and therefore the antecedent (X) must also be true. It’s the exact opposite of an if/then statement.



If the economy is doing badly, then jobs will be lost and wages will go down.


I lost my job last week. Therefore, the economy must be doing badly.

Bill’s premise and conclusion are both true. However, the logical fallacy occurs when he presumes that because he lost his job – which could be a consequence of a bad economy – the economy must be doing poorly. There are many other plausible reasons that he could have lost his job, even in the absence of poor economic conditions (HR dispute, poor performance, conduct violations, etc.), Don’t be like Bill. He is full of it.