 (The) distinction between geometry and physics is an error, physics extends not at all beyond geometry: the world is a \((3+1)\) dimensional metrical manifold, and all physical phenomena transpiring in it are only modes of expression of the metric field, …. (M)atter itself is dissolved in “metric” and is not something substantial that in addition exists “in” metric space. (1919: 115–116, translation by the author)