- reduction sentence
- A device proposed by Carnap for dealing with sentences of a scientific theory whose logical form is not easily given in the terms of the predicate calculus . ‘ x is soluble in water’ cannot be defined as ‘ x is placed in water →x dissolves’, since the → of the predicate calculus is material implication, and the consequence would be that all things not placed in water are soluble. Carnap's solution was to define ‘soluble’ only within the scope of being placed in water: if something is placed in water, then it is soluble if and only if it dissolves: ((∀x )(x is placed in water → (x is soluble ↔x dissolves))). The reduction sentence does not define solubility for other things.
Philosophy dictionary. Academic. 2011.