redefinition, high/low

Term introduced by the 20th-century American philosopher Paul Edwards for the manoeuvre of redefining a term more or less tightly, so that an apparently false statement is made true if interpreted in the new way. A high redefinition tightens the criterion of application: ‘No, he wasn’t drunk—to be drunk you have to be really comatose, after all.’ A low redefinition relaxes it: ‘You were drunk—a single sherry impairs one's faculties’. Edwards believed that philosophical disputes, e.g. over whether some process of forming belief counts as reasonable, were bedevilled by unwitting shifts of definition of the key terms.