The error of declaring certain claims to be facts and others to be false based on nothing but personal preference or tribal allegiance, ignoring evidence, expertise, and consistency. This fallacy is how someone can believe that vaccines are dangerous despite overwhelming scientific consensus, or that an election was stolen despite dozens of court cases and audits. Facts become a la carte: you pick what's true based on what feels good, what your team believes, or what serves your interests. The fallacy of arbitrary factuality is the death of shared reality, because if facts are just whatever you want them to be, then we're not having a conversation—we're just yelling at each other from different dimensions.
Example: "She committed the fallacy of arbitrary factuality in the group chat, declaring that a viral TikTok was 'facts' while dismissing a peer-reviewed study as 'just someone's opinion.' When asked why, she said the study 'felt wrong' and the TikTok 'felt right.' Facts, for her, were feelings, and reality was whatever she felt like believing."
by Dumu The Void February 15, 2026
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