A metaphorical entailment is the imparting of a characteristic of the source domain (the metaphorical image) to the target domain (the concept receiving metaphorical treatment) by logical means.
The metaphorical entailment “an argument defines a path” is derived from the premise that “a journey defines a path” and the argument-as-journey metaphor, whereby “an argument is a journey,” and which is expressed in the following sentences:
- He strayed from the line of argument.
- Do you followmy argument?
- I'm lost.
- You're going around in circles.