Sorites
An arbitrarily long series of premises consisting of concatenated universal quantifications (or conditionals) that can be replaced by a new universal quantification, constructed from the antecedent of the first premise and the consequent of the last.
This can be represented as a formula as follows:
All A are B.
All B are C.
…
All M are N.
Therefore, All A are N.
Chain argument
A variant of the Sorites that is based on conditional statements (instead of universal quantifications) is sometimes called a “chain argument”.
Since conditional statements can always be converted into universal ones, the following form is logically equivalent to the one listed above:
If A, then B.
If B, then C.
…
If M, then N.
Therefore, If A, then N.
Name
The name “sorites” comes from σωρός [sorós], the Ancient Greek word for a “pile” or “heap”. It is used as a shorter form for the latinized term “soriticus syllogismus” and should not be confused with the Sorites fallacy.
Other names
- Polysyllogism
- Multi-premise syllogism
- Modus Barbara – a specific form of the sorites with exactly three terms.
- Acervus
Example
All squares are rectangles.
All rectangles are parallelograms.
All parallelograms are trapezoids.
All trapezoids are quadrilaterals.
All quadrilaterals are polygons.
All polygons can be drawn in a continuous sequence of lines.
Therefore: All squares can be drawn in a continuous sequence of lines.
See also
More information
- Polysyllogism on Wikipedia