Externalist fallacy: A monolithic error common in scientistic assumptions whose fallacy may be defined as whatever adopts the following logical form of supposition or argument. What is observable as external phenomena rules out as valid what is internally experienced. The error of this ruling metaphysic proceeds in three steps: (1) what is not externally observable and (2) not measurable by a physical metric, is therefore (3) invalid or superfluous.
Source: ‘What is Good? What is Bad? The Value of All Values across Time, Place and Theories’ by John McMurtry, Philosophy and World Problems, Volume I-III, UNESCO in partnership with Encyclopedia of Life Support Systems: Oxford, 2004-11.