Aristotle’s apagoge, variously translated as abduction, reduction, or retroduction, is a form of reasoning common to two types of situations.
Abduction may be:
- The operation by which a phenomenon (a fact to grasp, to understand) is factored through an explanatory hypothesis, or
- The operation by which a problem (a fact to make, to accomplish) is factored through an intermediate construction.
Aristotle gives one example of each type in Prior Analytics 2.25. There is some discussion at the following location.