We reconsider differential geometry from the point of view of the quantum
theory of non-relativistic spinning particles, which provides examples of
supersymmetric quantum mechanics. This enables us to encode geometrical
structure in algebraic data consisting of an algebra of functions on a manifold
and a family of supersymmetry generators represented on a Hilbert space. We
show that known types of differential geometry can be classified in terms of
the supersymmetries they exhibit. Replacing commutative algebras of functions
by non-commutative *-algebras of operators, while retaining supersymmetry, we
arrive at a formulation of non-commutative geometry encompassing and extending
Connes' original approach. We explore different types of non-commutative
geometry and introduce notions of non-commutative manifolds and non-commutative
phase spaces. One of the main motivations underlying our work is to construct
mathematical tools for novel formulations of quantum gravity, in particular for
the investigation of superstring vacua.Comment: 125 pages, Plain TeX fil