  Einstein-Podolsky-Rosen (EPR) steering is an intermediate quantum correlation
that lies in between entanglement and Bell non-locality. Its temporal analogue,
temporal steering, has recently been shown to have applications in quantum
information and open quantum systems. Here, we show that there exists a
hierarchy among the three temporal quantum correlations: temporal
inseparability, temporal steering, and macrorealism. Given that the temporal
inseparability can be used to define a measure of quantum causality, similarly
the quantification of temporal steering can be viewed as a weaker measure of
direct cause and can be used to distinguish between direct cause and common
cause in a quantum network.
