Empiricists mostly prefer an epistemic notion of causality intending thereby to avoid metaphysical entanglements. General relativity however provides examples for causality without predictability, i. e. world models in which for geometrical reasons there exist no spacelike hypersurfaces containing traces of all future events. Yet local determinism for every single event remains valid in these cases. Therefore the problem arises how to account for a causal structure that implies local but not global predictability. This problem, it is argued, cannot be solved (...) by characterizing the causal connection of events itself by means of its epistemic aspects. Instead the ontological ground must be emphazised which allows for varying epistemic properties of causal connections according to the space-time structure. This can be done by use of the energy transfer concept of causality which involves no reminiscence of dubious natural necessity. (shrink)