  The aim of this paper is to make clear and precise the relationship between
the Rubin causal model (RCM) and structural causal model (SCM) frameworks for
causal inference. Adopting a neutral logical perspective, and drawing on
previous work, we show what is required for an RCM to be representable by an
SCM. A key result then shows that every RCM -- including those that violate
algebraic principles implied by the SCM framework -- emerges as an abstraction
of some representable RCM. Finally, we illustrate the power of this
conciliatory perspective by pinpointing an important role for SCM principles in
classic applications of RCMs; conversely, we offer a characterization of the
algebraic constraints implied by a graph, helping to substantiate further
comparisons between the two frameworks.
