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Atheist Claims About Logical Fallacies Often Just Mean: Shut Up!

In the recent debate, Matt Dillahunty accuses theists of “the fallacy of the argument from personal incredulity” because we examine his claims and find them incredible

What does atheist Matt Dillahunty mean when he accuses theists of “the fallacy of the argument from personal incredulity”?

Atheist rhetoric is a mish mash of ignorance, denial and pretense, often mingled with explicit or implicit efforts at censorship. Atheists travel in herds—contrary to their own inflated sense of their ‘freethought’ and ‘skepticism’, they are the most gullible idealogues. In debate with atheists, specific themes show up again and again, and atheist accusation of ‘the fallacy of the argument from personal incredulity’ is among the most common, usually aimed at Christians who challenge atheist arguments.

Matt Dillahunty invoked ‘the fallacy of the argument from personal incredulity’ in our recent debate.

It’s worthwhile examining what this ‘fallacy’ is and why atheists invoke it. This is a common definition:

Argument from Incredulity (also known as: argument from personal astonishment, argument from personal incredulity, personal incredulity)

Description: Concluding that because you can’t or refuse to believe something, it must not be true, improbable, or the argument must be flawed. This is a specific form of the argument from ignorance.

Logical Form:

Person 1 makes a claim.

Person 2 cannot believe the claim.

Person 2 concludes, without any reason besides he or she cannot believe or refuses to believe it, that the claim is false or improbable. – “Argument From Personal Incredulity” Logically Fallacious

If you are a bit perplexed by this “fallacy,” you’re on the right track. It’s nonsense, as we will see.

All beliefs are based on reasons of some sort, and all statements of belief are propositions — assertions that can be true or false. That is, statements of belief are opinions.

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To “argue from personal incredulity” means to state an opinion — i.e. to say “I don’t believe X.”

Opinions are inferences. Inferences connect evidence from experience to the best explanation, using some kind of formal reasoning. Both the evidence and the reasoning on which an opinion is based may be strong or weak. Some opinions are more reasonable than others.

Yet all opinions are based, in one way or another, on experience and reason. The experience may be careful systematic scientific experimentation or a lifetime of observation and reflection — or a mostly emotional reaction to a situation. The reasoning behind an opinion may be meticulous formal logic or slipshod hunches — or overtly fallacious logic.

It’s noteworthy that many good opinions are based on fallacies. For example, a common basis for opinion is abduction, which is a kind of inferential reasoning based on affirmation of the consequent, which is a fallacy.

Affirmation of the consequent takes the form:

If A, then B.


Therefore, A.

This is of course fallacious logic, yet many of our most reasonable and defensible opinions take this form. For example, consider:

If it’s raining, people on the street are wet.

People on the street are wet.

Therefore, it’s raining.

Although this is a deductive fallacy, it is usually true that when you see a lot of people on the street who are wet, that is because it’s raining. Possibly, of course, they are wet because they just ran under sprinklers, someone sprayed them with a hose, or they were all splashed by a huge truck passing through a puddle. But the inference to rain is reasonable, even though the logic is fallacious.

Most of our opinions are based on incomplete evidence evaluated by more or less dubious logic. Such is the human condition, and this is true of atheists as well as theists. But such opinions can still be true, and in fact, often are true. Most of the time, when people on the street are wet, that’s because it is raining.

We don’t live our lives systematically collecting reams of evidence and analyzing it by meticulous logic to make every decision. We have to decide on the run, with fleeting evidence and fuzzy logic, and yet we often get it right. If we waited for a well-controlled scientific study analyzed via formal logic to figure out if wet people on the street meant rain, we wouldn’t get much done.

So the atheist assertion that a theist is committing the “fallacy of argument from personal incredulity” just means that the theist is expressing an opinion. And an opinion itself cannot be a fallacy. Opinions can be right or wrong, well supported or poorly supported by evidence, and carefully or sloppily reasoned. Only logical assertions can be fallacies, and while an opinion contains logic (which is often technically fallacious), opinions cannot in themselves be fallacious. And many opinions based on scanty evidence and faulty logic are still quite good and true opinions.

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So what do atheists like Dillahunty mean when they accuse theists of “the fallacy of the argument from incredulity”? They mean that the theist has expressed an opinion with which the atheist disagrees. There is no “fallacy.” There are just different opinions, each one likely based on limited evidence and sketchy logic. Welcome to human life.

People express opinions — atheists as well as theists, and debates should turn on the quality of the evidence and logic, not on allegations of nonsensical “fallacies.” It is noteworthy that the “fallacy of argument from personal incredulity” is only invoked to discredit theist opinions. Atheists exempt their own opinions — their own “arguments from personal incredulity” — from the nonsensical label they apply to others. The denial of God’s existence is as good an “argument from personal incredulity” as any, but theists usually want to discuss evidence and logic, not invoke fictitious “fallacies” to shut down discussion.

So why do atheists like Dillahunty invoke this fictitious fallacy? The allegation of “the fallacy of argument from personal incredulity” is a tactic to suppress opposing opinions. It relieves the atheists of the burden of proving their case, which they are desperate to avoid. What atheists are really saying when they accuse theists of the ‘fallacy of argument from personal incredulity’ is that theists’ opinions are invalid by fiat and need no rebuttal. That is convenient for atheists who have no credible arguments of their own and no meaningful rebuttals to offer.

In short, the “fallacy of argument from personal incredulity” is just the atheists’ way of saying “shut up and don’t ask any more questions.” The way to counter it is to call it out for the nonsense that it is, and to keep asking questions. What atheists fear most is having to explain themselves, and the invocation of fictitious “fallacies” is one of their favorite ways to evade scrutiny.

The debate to date:

  1. Debate: Former atheist neurosurgeon vs. former Christian activist. At Theology Unleashed, each gets a chance to state his case and interrogate the other. In a lively debate at Theology Unleashed, neurosurgeon Michael Egnor and broadcaster Matt Dillahunty clash over the existence of God.
  2. A neurosurgeon’s ten proofs for the existence of God. First, how did a medic, formerly an atheist, who cuts open people’s brains for a living, come to be sure there is irrefutable proof for God? In a lively debate at Theology Unleashed, Michael Egnor and Matt Dillahunty clash over “Does God exist?” Egnor starts off.
  3. Atheist Dillahunty spots fallacies in Christian Egnor’s views. “My position is that it’s unacceptable to believe something if the available evidence does not support it.” Dillahunty: We can’t conclusively disprove an unfalsifiable proposition. And that is what most “God” definitions, at least as far as I can tell, are.
  4. Egnor now tries to find out what Dillahunty actually knows… About philosophical arguments for the existence of God, as he begins a rebuttal. Atheist Dillahunty appears unable to recall the philosophical arguments for God’s existence, which poses a challenge for Egnor in rebutting him.
  5. Egnor, Dillahunty dispute the basic causes behind the universe. In a peppery exchange, Egnor argues that proofs of God’s existence follow the same logical structure as proofs in science. If the universe begins in a singularity (where Einstein’s equations break down), what lies behind it? Egnor challenges Dillahunty on that.
  6. Is Matt Dillahunty using science as a crutch for his atheism? That’s neurosurgeon Michael Egnor’s accusation in this third part of the debate, which features a continued discussion of singularities, where conventional “laws of nature” break down. If the “supernatural” means “outside of conventional nature,” Michael Egnor argues, science routinely accepts it, based on evidence.
  7. Dillahunty asks 2nd oldest question: If God exists, why evil? In the debate between Christian neurosurgeon Michael Egnor and atheist broadcaster Matt Dillahunty, the question of raping a baby was bound to arise.
    Egnor argues that there is an objective moral law against such acts; Dillahunty argues, no, it is all just human judgment.

You may also wish to read:

Science can and does point to God’s existence. Michael Egnor: Natural science is not at all methodologically naturalist — it routinely points to causes outside of nature. If we are to understand natural effects, we must be open to all kinds of causes, including causes that transcend nature.


The Divine Hiddenness argument against God’s existence = nonsense. God in Himself is immeasurably greater than we are, and He transcends all human knowledge. A God with whom we do not struggle — who is not in some substantial and painful way hidden to us — is not God but is a mere figment of our imagination.

Michael Egnor

Senior Fellow, Center for Natural & Artificial Intelligence
Michael R. Egnor, MD, is a Professor of Neurosurgery and Pediatrics at State University of New York, Stony Brook, has served as the Director of Pediatric Neurosurgery, and award-winning brain surgeon. He was named one of New York’s best doctors by the New York Magazine in 2005. He received his medical education at Columbia University College of Physicians and Surgeons and completed his residency at Jackson Memorial Hospital. His research on hydrocephalus has been published in journals including Journal of Neurosurgery, Pediatrics, and Cerebrospinal Fluid Research. He is on the Scientific Advisory Board of the Hydrocephalus Association in the United States and has lectured extensively throughout the United States and Europe.

Atheist Claims About Logical Fallacies Often Just Mean: Shut Up!