The ethical tension over whether countries have differentiated responsibilities for climate change mitigation evokes the tale of a master and a man. The one who thinks she is the master is analogous to the wealthier, industrialized nations and their market actors, and the human is the rest of humanity, particularly those citizens of less developed countries. Since 1992, there has been formal, stated agreement that there should be differentiated responsibilities for climate change mitigation between developed and developing nations, but differentiation (...) remained a sticking point in negotiations over implementation at Copenhagen in 2009. Putting the parties in the climate change differentiation debate in analogy with the characters of Tolstoy’s story, “Master and Man,” this paper seeks to advance the common appreciation for the moral foundations of differentiation. (shrink)