The Fallacy Fallacy

by | Jan 20, 2021


During George W. Bush’s presidency I read an opinion piece that contained the following nugget of wisdom: “Just because W says it, doesn’t mean that it’s untrue.” This notion is simple yet profound. Just because you usually disagree with or dislike the messenger doesn’t mean that their message is false. (Note that the flip side is also true: just because you usually agree with or like the messenger doesn’t mean that what they say is true.)

A similar notion is found in what is known as “The Fallacy Fallacy” or “Argumentum ad Logicam” or “Argument from Fallacy” which provides that even though an argument might be fallacious, that doesn’t necessarily render the conclusion false. The Fallacy Fallacy takes the following form

If A then C

A is a fallacious argument

Therefore, C is false

The key concept behind this fallacy is that an argument for a conclusion and the conclusion itself are independent. In other words, a conclusion can be true regardless of why we think it is true.

Here are some examples;

1. All vegans are Democrats. Anne is a vegan, so she must be a Democrat.

Of course, not all vegans are Democrats. But Anne might still be a Democrat. Just because the reasoning behind why Anne is a Democrat is fallacious doesn’t mean that she’s not a Democrat.

2. Athletes perform poorly after being appearing on the cover of Sports Illustrated because they are jinxed.

It is true that athletes tend to perform more poorly after appearing on the cover of Sports Illustrated but this occurs due to Regression to the Mean, not because they are jinxed. The fallacious reasoning of why athletes’ performance declines after a cover appearance doesn’t render false the conclusion that athletes who appear on an SI cover tend to experience a drop-off in performance.

3. Seasons change because the Earth’s orbit takes it closer and further from the Sun. When it’s closer, summer occurs, when the Sun is more distant, winter occurs.

As we are all aware, seasons do change on our planet, but they occur because the Earth spins on a tilted axis which causes the hemispheres to tilt towards or away from the Sun, not because the Earth is closer or more distant to the Sun. Instead, summer occurs when the hemisphere you inhabit tilts towards the Sun, and likewise, winter happens when the tilt is away from the Sun. Just because the reasoning behind the change in seasons in the above example is wrong doesn’t mean that seasons don’t change.


  1. Happy Anniversary. Keep up the good work.

    Enjoyed your “What I’ve Learned” observations today. Sad, but insightful.

    Just FYI: The Earth does not wobble or experience a tilting motion as it orbits the Sun. The Earth is tilted relative to the North/South axis of the Sun. The Earth maintains that fixed tilt as it orbits the Sun. In the summer the Northern Hemisphere tilt bias is closer to the Sun. In the winter the Northern Hemisphere tilt bias is farther from the Sun.

    On the Winter and Spring Equinoxes, the tilt bias is neither toward or away from the Sun; they are equal. Try it with a tennis ball. Mark the ball with a magic marker about 20 degrees away from what would be the true North Pole. Tilt the ball so the North Pole assumes the position of he 20 degree mark and it is pointed directly to your right. Then, rotate yourself 360 degrees holding the ball in front of you and maintaining the exact same 20 degree tilt bias to the right relative to your line of site. When you start your rotation, it represents the Spring Equinox. When you rotate 90 degrees the North Pole is pointing directly toward you but 20 degrees lower than what would otherwise appear to you as the North Pole. When you get to 270 degrees, the North Pole on the ball will be hidden from you line of sight because the tilt bias takes it 20 degrees below the horizon.

    • Ok. Thanks. Wow I misunderstood. I’ll edit. Total fallacy in my part.

  2. While the earth wobbles, that isn’t what causes seasons. Its because the axis of rotation is tilted vs the plane of orbit. In the Northern Hemisphere’s summer, the tilt is towards the sun. 6 months later, that tilt is away from the sun

    • We’re saying the same thing. The wobble causes the axis to tilt which causes seasons. Why does the earth wobble? This IFOD is about a leading theory:

      • Isn’t all that a description of the mechanism that makes some parts of the earth to get closure to sum during a summer period? I.e. after all the summer happens when earth gets closer to sue;-)


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