Fallacies 'R Us

After debating with religious people on Twitter for a number of months (mostly Christians, some Muslims and a few... stray bullets), I thought to myself that all arguments for gods are based on flawed logic. A short convo confirmed that, indeed, my fellow atheists on Twitter believe the same. This is a short list with the most common logical fallacies I've encountered. This post will be updated to incorporate new fallacies when they present themselves.

The Fallacy Fallacy

Warning: Using flawed logic doesn't mean that your conclusion is necessarily wrong, it just means that you cannot base your conclusion on that logic. Let's think about an example to clarify this. Suppose you are going to visit your family, and they ask you at what time you'll arrive. You take into account the inevitable traffic jam and estimate an hour. Then, you step into your car and lo and behold, there is no traffic jam... but you get a flat tire. You arrive at the estimated time, but not because of the traffic jam you were worried about.

The same applies to the arguments in favor of gods. The fact that all arguments are based on flaws doesn't mean there are no gods... It just means that the religious shouldn't base their faith on those flawed arguments.

Saying that all arguments in favor of gods are flawed and concluding therefore that there are no gods is the fallacy fallacy.

The Proof by Assertion Logical Fallacy

Saying that something is true, doesn't make it true. Repeating a lie doesn't make it true either.
  • God exists
  • There is a heaven / hell
  • As sure as there is a god
  • Allah Akbar
Only affirmations based on evidence should be given any credibility. “Gravity exists” is not an assertion logical fallacy, because we experience it daily. Julius Caesar was an historical figure because there are historical accounts and archaeological evidences that he, indeed, existed.
  • The evidence of god is everywhere. Look around you
This is still an assertion logical fallacy. Whatever we can observe is called “reality”. Supernatural gods, cannot be observed as per definition. Saying that gods obey the laws of nature is admitting that gods are powerless... nonexistent.

The Appeal to Authority Logical Fallacy

It's very easy to confide in the knowledge of others, especially when they are presented as experts.
  • Parents say that god exists
  • Preachers say that god exists
  • Teachers say that god exists
  • Weird people on street corners say that god exists
Parents, preachers, teachers and weird people commit the assertion logical fallacy... and you believe their affirmation, which is the appeal to authority logical fallacy.
  • Einstein, Newton (or others) believed in god
Whatever somebody (Einstein or whomever) believed is irrelevant, as long as they have not provided any evidence for the existence of gods. Basing your believe on the believe of others is not basing your believe on anything solid.

The Bandwagon Logical Fallacy

The fact that loads of people think that something is true, doesn't mean that it's actually true. Not so long ago, everybody thought the sun revolved around the earth. Then Copernicus came and, posthumously, changed all that. Now we know the earth revolves around the sun, and the sun around a massive black hole in the center of the milky way.
  • 2 Billion Christians/Muslims can't be wrong (the numbers change somewhat, sometimes)
  • Islam is the fastest growing religion on earth, therefore it's true

The Anecdotal Logical Fallacy

This is one of my favourites. Somebody tells you a story and you believe the story. For instance, Mary told Joseph that she was inseminated by the Holy Spirit (if you accept the story that they actually existed).
  • The old testament featured talking bushes
  • The apostles wrote eye witness accounts of Jesus
  • The Koran features Muhammad rising to heaven on a winged, flying, horse.
The 'holy' books contain stories. Maybe these are true, maybe not. Most of these stories are impossible to verify, especially when containing supernatural events. That's why I call the bible the tallest tale ever told (paraphrasing George Carlin). 

The Appeal to Emotion Logical Fallacy

Somebody tries to join two unrelated issues with an emotional link. Think about all the people that suffer hunger; eat. The fact that you eat (or not) doesn't affect the person who suffers hunger in any way. If you actually want to help people who suffer hunger, you can give to a charity that feeds them... or that teaches them how to fish.
  • Jesus died for your sins
  • Missionaries put their lives on the line
  • Martyrs died for their faith
  • God loves you (+ Assertion Logical Fallacy)
Appealing to Jesus' death is emotional blackmail. The logical fallacy is to try to do something for Jesus, as he can't be repaid... ever.
(Some) Missionaries are putting their lives at risk, voluntarily. So what? That proves they believe in their deity. It is not evidence for the deity actually existing.
Dead missionaries are martyrs. Same thing. It's no evidence for gods.

Note: The appeal to fear logical fallacy was brought to my attention shortly after publishing this. It's a special case of appeal to emotion logical fallacy.
  • You'll burn in hell (with caps lock)

Circular Logic Logical Fallacy

In formal logic, basing your premise on your conclusion on your premise on your conclusion.... is a flaw. Stating that something is True, because it's True doesn't make it true. It's an elaborate Assertion Logical Fallacy.
  • The bible is true because it says so in the bible
  • The creator created the creation (look around you)
  • God sacrificed himself, to himself, to save you from himself.

    Source: atheistforum.wordpress.com

Non-sequitur Logical Fallacy

This means 'it doesn't follow'. If Aristotle is a man, therefore the sky is blue.
  • We don't know therefore gods
Mostly, this fallacy is used with the god of the gaps idea. If there's a gap in the scientific knowledge that's where gods are (Which god?)

Special pleading Logical Fallacy

This fallacy occurs in conjunction with the above, non-sequitur god of the gaps.
  • What caused the first cause? Ah, gods are uncaused.
Also known as the Kalam Cosmological Fallacy.

Black or white Logical Fallacy

Ever heard of Pascal's wager? He said that you're better of believing in 'god' because of the chance of ending in hell was smaller. That might be so if there would only be one god. But there are thousands. According to Christians, non-christians will go to hell. According to muslims, non-muslims will go to hell... So, with only Yahweh and Allah, your chances of going to hell are getting worse... if there are gods, that is.

Logical Fallacy of Confusion

The aim of this logical fallacy is to render the conversation useless by confusing the opponent. The person utters total nonsense. For instance: Creationists like to talk about 'Kinds' which has no scientific definition.

  • "God made the wild animals according to their kinds" Genesis 1:25 
How can creationists claim that the domestic cat and the lion are of the same kind, as some do, saying that 'kind' equates to family?

Logical Fallacy of Equivocation

Similar to the last logical fallacy, this one misuses the meaning of words. For instance, belief.

  • Do you believe things without evidence?
Well, yes, I do. Not all beliefs are religious beliefs and I can believe loads of things without evidence. I can believe my wife is faithful to me, without evidence. I can believe that the state will provide a hospital when I need one. I can believe the snake-oil salesman. The important part isn't what I can believe or not believe, but what is rational. 

Selective Attention Logical Fallacy

FimusTauri commented on this logical fallacy, also known as Cherry Picking. The verses of the holy books that appeal to the reader are considered true, while the verses that are not are ignored.

--- Help me add the logical fallacies I've missed. Thanks for reading.


  1. Hi Hans,

    I have a new one for you. I haven't heard this anywhere else so I'm not sure if there's an official name for it - for now I just call it the false fallacy fallacy.

    I see it all the time on Twitter. Basically it's using a false accusation of fallacy of your opponent in order to divert from the point made. Usually they use the ad hominem fallacy. For example, an atheist tweets a theist with a logical point followed by "you dope" or some other insult. The theist then fucuses only on that, accusing them of an ad hominem fallacy and the thread turns into a debate over the definition of ad hominem.

  2. I think that's a Red Herring Logical Fallacy. http://en.wikipedia.org/wiki/Red_herring

    1. It would be similar to a red herring, although a bit different as it's more of a selective criticism of an opponent's argument, rather than an irrelevant argument created to distract from the topic.

  3. The Godless nature of the cosmos is blatantly obvious; i can not comprehend the need to construct an intelligent, articulate argument against nonsense.

  4. Without the intelligent arguments; many atheists like myself would still be theists. Thank you Hans. : )


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