 Going forward, Russell retained the view that sense data (or their counterparts) provide epistemological bedrock. But within a year or so, in Our Knowledge of the External World (1914a) and “The Relation of Sense-data to Physics” (1914b), he changed position on the metaphysics of sense data in relation to material objects. He came to view such objects as logical constructions out of sense data. He found no need to assert the existence of material objects, whether the substantial “thing” of common sense or the atoms and molecules of physics (1914b: 109, 114–115). Rather, he populated the world with minds and sense data and new entities termed “sensibilia”. Things and micro-physical particles became logical constructions, not inferred entities as in his representative realism of 1912. This adjustment may be seen as an extension of his recognition that sense data are very well known. Treating material objects as mere logical constructions avoids a shaky inference from well-known data to the actual existance of physical things.