  Turner’s preferred models of T are the pairs &lt;I, S&gt; such that: (1) &lt;I, S&gt; satisfies T, (2) S = {I}, and (3) &lt;I, S&gt; is the unique interpretation &lt;I′, S′&gt; meeting conditions (1) and (2) with I′ = I. Condition (2) guarantees the “universality of causation”; it validates A ↔ [ c ]A. Condition (3) “grounds” causality in noncausal information (in the models in which we are interested, this will be information about the occurrence of events), in the strongest sense: it is uniquely determined by this information.