Continuum Fallacy
Continuum Fallacy
Also known as: the sorites fallacy, the fallacy of the beard, the heap, the line-drawing fallacy
Description
The continuum fallacy is the claim that because there is no sharp boundary between two states, there is no real difference between them, or that a category is meaningless because its edges are vague. One grain of sand is not a heap and adding one grain never turns a non-heap into a heap, so (the argument runs) there are no heaps. The reasoning fails because vagueness at the boundary is compatible with clear cases at the centre: there is no exact moment at which dusk becomes night, and night is still different from day.
Form
- There is no precise point at which X becomes Y.
- Therefore there is no meaningful distinction between X and Y (or: the category Y is useless).
Examples
- "There is no exact age at which a child becomes an adult, so age limits are arbitrary and should be abolished."
- "Species blend into one another over evolutionary time, so 'species' is not a real category." (The evolutionary continuum is real; so are dogs and cats.)
- "There are intersex conditions and hard cases, so the categories of male and female are meaningless." See Sex and Gender, where I argue that the existence of difficult cases does not by itself make a category useless, and, in the other direction, that the usefulness of a category does not justify every application of it.
- The reverse form, used by the other side of the same arguments: "the category is useful, therefore its boundary is sharp and every borderline case must be forced to one side."
Notes
- The fallacy is the argumentative use of the ancient sorites paradox. The paradox is a genuine puzzle about vague predicates; the fallacy is the move from "vague" to "empty".
- The remedy is usually Ludwig Wittgenstein's: ask what the distinction is for in this context (Language Games). A medical classification, a sporting eligibility rule and a social description can draw the line in different places for different purposes, and none of them needs the line to be sharp everywhere to be useful somewhere.
- Neighbours: the Slippery Slope (which treats a continuum as a conveyor belt), the False Dilemma (which denies the continuum altogether), and Equivocation (which exploits the vagueness to shift meaning mid-argument).