Fallacies of Ambiguity
Fallacies of ambiguity are informal fallacies that arise when an argument contains multiple possible interpretations — of a word, phrase, sentence structure, or emphasis — and the argument’s apparent success depends on exploiting that ambiguity. When the ambiguity is resolved, the argument collapses.
How It Appears Per Course
PHIL 252
The core content of Unit 6. Six types are covered: equivocation, amphiboly, accent, composition, division, and hypostatization.
The Six Fallacies
1. Equivocation
A key word is used in two or more senses within the same argument. The argument’s apparent transitivity depends on treating these different senses as the same.
“Knowledge is power. Power corrupts. Therefore, knowledge corrupts.” — “power” shifts from “capability/influence” to “political dominance”
Equivocation blocks transitivity — the middle term can’t bridge the two premises if it means different things in each.
2. Amphiboly
Structural ambiguity in the grammar of a sentence — the sentence can be read in multiple ways, making it unclear what is actually being asserted.
“Mary and Frieda are visiting doctors.” — Are they doctors themselves visiting somewhere, or are they visiting doctors?
“Bill became disgusted with Fred at Mary’s party, so he went home in a funk.” — Who went home?
3. Accent
Ambiguity arising from unclear stress or emphasis — meaning changes depending on which word is stressed or what tone of voice is intended.
“Did you steal the butter?” (emphasis on you — accusing this person specifically)
“Did you steal the butter?” (emphasis on steal — the manner of acquisition)
“Did you steal the butter?” (emphasis on butter — maybe the cheese was okay to take)
4. Composition
Invalidly attributing a property of the parts or members to the whole or class.
The key question: is the property hereditary (does it genuinely pass from parts to wholes)? Some do (a pile of red blocks is red). Many don’t.
“Every atom in my arm is invisible. Therefore, my arm is invisible.” ✗
“Every player on the team is a superstar. Therefore, the team is a superstar team.” ✗ (team chemistry, coordination, etc. matter independently)
5. Division
The reverse of composition — invalidly attributing a property of the whole or class to an individual part or member.
“University graduates earn 70% more on average. Kofi is a graduate. Therefore, Kofi earns 70% more.” ✗
“This vase is part of a valuable collection. Therefore, this vase is valuable.” ✗ (value may arise from the collection as a whole)
6. Hypostatization
Treating an abstract term or metaphor as if it were a concrete entity — as if it has agency, body, or intentions.
“The state butts into private affairs and makes a mess of things.” (The state is treated as an agent with hands and intentions)
“Canada has a black eye.” (Canada personified as a body)
“Whenever Nature calls…” (Nature as an agent)
Hypostatization misleads because it makes indeterminate abstractions appear to be discrete, acting entities with definable properties.
Composition and Division: The Property Heredity Test
| Property | Hereditary? | Fallacy Risk |
|---|---|---|
| ”Red” | Yes (parts to whole) | Lower |
| ”Silent” | No (a silent choir member ≠ silent choir) | Composition risk |
| ”Average salary” | No (applies to group, not individuals) | Division risk |
| ”Valuable” | Depends on source of value | Both risks |
Cross-Course Connections
InformalFallacies — these are a subset of informal fallacies
Definition — equivocation occurs when definitions shift mid-argument
ClassificationSystems — composition/division confuse levels of a classification hierarchy
Argument — all six fallacies corrupt the argument’s support relationship
Key Points for Exam/Study
- All six involve multiple interpretations — ambiguity is the common thread
- Equivocation: word-level ambiguity; blocks transitivity of the middle term
- Amphiboly: sentence-structure ambiguity; grammar allows multiple readings
- Accent: stress/emphasis ambiguity; tone changes meaning
- Composition: parts→whole (is the property hereditary in this direction?)
- Division: whole→parts (is the property hereditary in this direction?)
- Hypostatization: abstract→concrete (don’t personify abstractions)
- For composition/division, always ask: “Does this property actually transfer across levels?”