 Three theoretical developments come together for von Neumann in his theory of continuous geometries during the seven years following 1932: the algebraic approach to quantum mechanics, quantum logics, and rings of operators. By 1934, von Neumann had already made substantial moves towards an algebraic approach to quantum mechanics with the help of Jordan and Wigner – their article, “On an Algebraic Generalization of the Quantum Mechanical Formalism”,  is reprinted in von Neumann (1961–1963, Vol. II, No. 21). In 1936, he published a second paper on this topic, “On an Algebraic Generalization of the  Quantum Mechanical Formalism (Part I)”, which is reprinted in von Neumann (1961–1963, Vol. III, No. 9). Neither work was particularly influential, as it turns out. A related paper by von Neumann and Birkhoff, “The Logic of Quantum Mechanics”, was also published in 1936, and it is reprinted in von Neumann (1961–1963, Vol. IV, No. 7). It was seminal to the development of a sizeable body of literature on  quantum logics.  It should be noted, however, that this happens only after modularity, a key postulate for von Neumann, is replaced with orthomodularity (a weaker condition). The nature of the shift is clearly explained in Holland (1970): modularity is in effect a weakening of the distributive laws (limiting their validity to certain selected triples of lattice elements), and orthomodularity is a weakening of modularity (limiting the validity of the distributive laws to an even smaller set of triples of lattice elements). The shift from modularity to orthomodularity was first made in (Loomis 1955). Rapid growth of literature on orthomodular lattices and the foundations of quantum mechanics soon followed. For example, see Pavičić (1992) for a fairly exhaustive bibliography of quantum logic up to 1990, which has over 1800 entries.