By means of a legal-philosophical investigation devoted to the issue of intergenerational justice, in this paper I seek to scrutinize the paradigmatic reach of the category of mercy, so strongly evoked by Pope Francis. As a result of such a strategy, I attempt to show how mercy, for fruitful it may be in counterbalancing contractarian-based understandings of justice, nonetheless encounters a peculiar temporal predicament when asked to engage the problem of duties towards future others. My counterproposal, however, is that to over- come mercy’s shortcomings one does not have to discard it. Rather one needs to back it up via a phenomenological drawing on the Lévinassian notion of «ethical resistance» as genuinely able to tackle with what a future alterity demands on us.