Adolf Grünbaum maintains that, within the framework of special relativity, the relation of simultaneity relative to an inertial observer is conventional rather than factual in character. His argument turns on two assertions:(1) The relation is not uniquely definable in terms of the relation of causal connectibility. But Malament's own argument against (1), as he construes it, proceeds without reference to the merits or demerits of the causal theory of time, since his concern is to refute (1) within the framework of a causal theory of temporal order "even while avoiding debate over