  A mathematical definition of classical causality over discrete spacetime
dynamics is formulated. The approach is background free and permits a
definition of causality in a precise way whenever the spacetime dynamics
permits. It gives a natural meaning to the concepts of cosmic time, spacelike
hypersurfaces and timelike or lightlike flows without assuming the notion of a
background metric. The concepts of causal propagators and the speed of
causality are discussed. In this approach the concepts of spacetime and
dynamics are linked in an essential and inseparable whole, with no meaning to
either on its own.
