Arbitrary Obsolescence Fallacy

The claim that socialism and communism are outdated ideologies from the 19th century, while capitalism is presented as timeless, natural, and permanently relevant—despite capitalism also being a 19th-century ideology that has changed dramatically over time. This fallacy arbitrarily declares one set of ideas expired while granting another eternal freshness, based on nothing but preference. It's like saying horses are outdated but cars are forever, ignoring that cars will also be obsolete someday, and that the criteria for "outdated" are entirely made up. The arbitrary obsolescence fallacy allows capitalism's defenders to avoid engaging with socialist critiques by simply declaring them old, as if age determined validity rather than, you know, evidence and argument.

*Example: "In the debate, he deployed the arbitrary obsolescence fallacy: 'Socialism is a 19th-century idea that failed everywhere it was tried. Capitalism is modern, dynamic, the future.' She pointed out that capitalism was also a 19th-century idea, that it had also failed many people, and that 'modern' was just a vibe, not an argument. He responded with 'but look at the stock market.' The fallacy held strong."*

by Dumu The Void February 15, 2026

Arbitrary Reality Fallacy

The logical error in which something is considered true or false based on arbitrary, often self-serving criteria rather than evidence or consistent standards. This fallacy is rampant in politics and economics, where the same person will demand "rigorous proof" for climate science while accepting election fraud claims based on a single Twitter post. Truth becomes a menu: you pick what you want to believe, and reality is just whatever supports your side. The arbitrary reality fallacy is how people can look at the same economy and one sees booming success while another sees crushing failure—both are looking, neither is using a consistent measuring stick, and both are convinced the other is delusional.

Example: "He used the arbitrary reality fallacy in every argument. When she cited unemployment statistics, he said government data was fake. When she cited private research, he said it was biased. When she cited his own previous statements, he said he'd been misquoted. Reality, for him, was whatever allowed him to win the argument. She stopped arguing, because you can't debate someone who brings their own facts and changes them as needed."

by Dumu The Void February 15, 2026

Arbitrary Non-Correlation Fallacy

A common online debating tactic where someone dismisses a valid connection between two things by arbitrarily declaring them unrelated, often without evidence or reasoning. For example, when you point out that billionaires exist alongside homelessness, and someone responds that "those things have nothing to do with each other"—as if wealth accumulation and poverty exist in separate universes. The arbitrary non-correlation fallacy is the rhetorical equivalent of covering your ears and saying "la la la not connected." It's especially popular in discussions about systemic issues, where acknowledging connections would require acknowledging problems, which is inconvenient when you're trying to defend the status quo.

Example: "She posted a graph showing that as CEO pay skyrocketed, worker wages stagnated. The first comment was pure arbitrary non-correlation fallacy: 'Those two things aren't related. CEO pay is about talent and markets. Worker wages are about productivity. Different things.' She posted five studies showing the connection. He posted 'correlation isn't causation.' She posted the causation studies. He posted 'still not convinced.' The fallacy had done its job: preventing learning, preserving ignorance."

by Dumu The Void February 15, 2026

Arbitrary Fallacy

The meta-fallacy of committing a fallacy simply because you've decided that logic doesn't apply to you, your argument, or your preferred conclusions. It's the rhetorical equivalent of playing chess and declaring that your pieces can move however you want because you've decided the rules are arbitrary. The arbitrary fallacy encompasses all other fallacies, but with the added twist that the person committing it knows they're being illogical and simply doesn't care. They've decided that their truth is truer than your facts, their logic is logicaler than your logic, and no amount of reasoning will change their mind because reasoning is just, like, your opinion, man.

Example: "He committed the arbitrary fallacy in every debate. When presented with evidence, he said evidence was unreliable. When presented with logic, he said logic was a Western construct. When asked what he would accept, he said 'common sense,' which meant whatever he already believed. There was no way to win, because he had declared the game rigged and was playing by his own rules, which changed constantly."

by Dumu The Void February 15, 2026

Arbitrary Burden of Proof

The meta-fallacy where one side is forced to prove every assertion, back every claim, and satisfy every demand for evidence, while the other side can simply move goalposts, demand new sources, dismiss evidence as insufficient, and never provide anything themselves. The arbitrary burden of proof is the debate equivalent of one person carrying a piano while the other skips ahead, occasionally turning around to complain that the piano-carrier isn't keeping up. It's how conspiracy theorists can demand that scientists prove negatives (prove that vaccines don't cause autism, prove that the moon landing wasn't fake), while offering no proof for their own claims and dismissing any evidence against them as part of the conspiracy.

Example: "She was trapped under an arbitrary burden of proof. Every time she provided a source, he moved the sourcepost. Every time she met his standard, he raised it. After two hours, she'd provided twenty sources, and he'd provided zero. When she asked what he believed, he said 'I'm just asking questions.' The questions were infinite, the answers were never enough, and the burden was hers alone."

by Dumu The Void February 15, 2026

Arithmomerophobia

A specific form of mathematical anxiety characterized by an intense aversion to, or fear of, rational numbers (fractions and decimals) when encountered within algebraic structures.

I was doing fine with the algebra homework until the teacher added decimals. My arithmomerophobia kicked in and I just stared at the page for twenty minutes

by Cobear15 February 25, 2026

Arbitrary Analogy Fallacy

A fallacy where one dismisses an argument, claim, or position by comparing it arbitrarily to something universally derided—Flat Earth theory, anti-vaxxers, tinfoil hats, or other culturally recognized symbols of irrationality—without establishing a substantive logical connection. The fallacy lies in the arbitrariness of the comparison: rather than engaging with the actual argument, the speaker simply invokes a stigmatized label, relying on cultural disgust to do the work of refutation. "That's just like Flat Earthers." "You sound like an anti-vaxxer." "Next you'll be wearing a tinfoil hat." The comparison is arbitrary because the logical relationship between the target argument and the stigmatized position is never demonstrated—they're just associated through rhetorical gesture. This fallacy is particularly powerful because it bypasses reasoning entirely, triggering emotional rejection rather than intellectual engagement. It's the lazy debater's way of dismissing without thinking.

Example: "He raised legitimate questions about media consolidation, and she responded with 'oh, so you're a conspiracy theorist now?'—Arbitrary Analogy Fallacy, using the stigma of conspiracy to avoid engaging with actual concerns."

by Dumu The Void March 17, 2026