Abstract
The main algebraic foundations of quantum mechanics are quickly reviewed. They have been
suggested since the birth of this theory till up to last years. They are the following ones: Heisenberg-Born-
Jordan’s (1925), Weyl’s (1928), Dirac’s (1930), von Neumann’s (1936), Segal’s (1947), T.F. Jordan’s (1986),
Morchio and Strocchi’s (2009) and Buchholz and Fregenhagen’s (2019). Four cases are stressed: 1) the
misinterpretation of Dirac’s algebraic foundation; 2) von Neumann’s ‘conversion’ from the analytic approach of
Hilbert space to the algebraic approach of the rings of operators; 3) Morchio and Strocchi’s improving Dirac’s
analogy between commutators and Poisson Brackets into an exact equivalence; 4) the recent foundation of
quantum mechanics upon the algebra of perturbations. Some considerations on alternating theoretical
importance of the algebraic approach in the history of QM are offered. The level of formalism has increased
from the mere introduction of matrices to group theory and C*-algebras but has not led to a definition of the
foundations of physics; in particular, an algebraic formulation of QM organized as a problem-based theory and
an exclusive use of constructive mathematics is still to be discovered.