Definition
Special Pleading (or ad hoc reasoning) is the arbitrary introduction of new elements or excuses into an argument to save a cherished belief from contradictory evidence. It involves “jerry-rigging” the argument as needed to maintain its apparent validity.
Why It Matters
Identifying special pleading is the ‘bullshit filter’ for rational discourse; it prevents an argument from being saved by arbitrary, ad hoc excuses, ensuring that cherished beliefs are subject to the same evidentiary standards as any other claim.
Core Concepts
- Ad Hoc Excuses: Inventing reasons why a phenomenon failed to appear under test conditions (e.g., “ESP doesn’t work in the presence of skeptics”).
- The Invisible Dragon: Carl Sagan’s metaphor for a claim that is made unfalsifiable through a series of special pleadings (the dragon is invisible, incorporeal, heatless, etc.).
- Immunization against Evidence: Special pleading makes a theory “evidence-proof” by explaining away every failure without providing independent support for the new excuse.
- Case Studies:
- Bigfoot: “They hide because they are psychic/teleport/burn their dead.”
- Quackery: “The study failed because the wrong type of needle/vibration was used.”