  Ryckman (2005) describes the history of relativity theory and Weyl's role in it. Ryckman argues that the work of Eddington and Weyl was profoundly influenced by the phenomenology of Husserl. The latter also seems to have understood objectivity in terms of invariance. (Ryckman calls Kantian structural realism “transcendental structuralism”. OSR is what he calls ‘transcendent structuralism’.) Group theory in the development of structuralism deserves further historical analysis. It played a crucial role in epistemological reflections on geometry in relation to Klein's Erlanger programme (Birkhoff and Bennett 1988). French (1998, 1999, 2000) and Castellani (1998) have explored the ontological representation of the fundamental objects of physics in terms of sets of group-theoretic invariants by Cassirer, Eddington, Schrödinger, Weyl, Wigner, Piron, Jauch and others. On the other hand, Roberts (2011) criticizes the idea that structure can be understood as group structure in the context of quantum physics. 