Causal mediation analysis is complicated with multiple effect definitions that require different sets of assumptions for identification. This article provides a systematic explanation of such assumptions. We define five potential outcome types whose means are involved in various effect definitions. We tackle their mean/distribution’s identification, starting with the one that requires the weakest assumptions and gradually building up to the one that requires the strongest assumptions. This presentation shows clearly why an assumption is required for one estimand and not another, (...) and provides a succinct table from which an applied researcher could pick out the assumptions required for identifying the causal effects they target. Using a running example, the article illustrates the assembling and consideration of identifying assumptions for a range of causal contrasts. For several that are commonly encountered in the literature, this exercise clarifies that identification requires weaker assumptions than those often stated in the literature. This attention to the details also draws attention to the differences in the positivity assumption for different estimands, with practical implications. Clarity on the identifying assumptions of these various estimands will help researchers conduct appropriate mediation analyses and interpret the results with appropriate caution given the plausibility of the assumptions. (shrink)

In 1994 Elizabeth Stuart addressed the situation of the lesbian and gay community with regard to its relationship with Church, Community and with Feminism. Since writing the 1994 paper she has engaged in more reflection on the nature of desire in the light of the tragedy of human relating. If desire cannot have its telos, its fulfilment in human relating which is fragile and mortal and yet can enable us temporarily to create room in ourselves for others, then it must (...) point beyond itself and have its end beyond us in God. (shrink)