Consider this proposed inference:
1. Every ʿayn is a source of spring-water.
2. The human eye is a ʿayn.
3. Therefore the human eye is a source of spring-water.
In the first premise “ʿayn” denotes a spring; in the second, an eye. The syllogism therefore does not possess a single unchanging middle term.
When the two senses are represented by different terms, the missing connection becomes obvious. This is the fallacy of equivocation, not a valid inference.
Opening interactive controls...
Causes of Error: Misunderstanding and Verbal Ambiguities
Consider this proposed inference:
1. Every ʿayn is a source of spring-water.
2. The human eye is a ʿayn.
3. Therefore the human eye is a source of spring-water.
In the first premise “ʿayn” denotes a spring; in the second, an eye. The syllogism therefore does not possess a single unchanging middle term.
When the two senses are represented by different terms, the missing connection becomes obvious. This is the fallacy of equivocation, not a valid inference.