 Here the instantiation of \(E\) is sufficient to determine the instantiation of the cluster. Baumgartner’s suggestion requires an effect to have at least two alternative sufficient clusters in order to establish the direction of causation. And even then, it seems that the problem of joint effects of a common cause is still unsolved. Consider  Figure 2,  where \(A\) and \(B\) are the joint effects of a common cause \(C\), and \(D\) and \(E\) are alternative causes for \(A\) and \(B\), respectively.