 Lewis delivered counterpart theory as part of his modal realism, but the core idea can be separated from this background, and even from the assumption of world-bound agents. (See e.g. Stalnaker 1986, Heller 1998, Sider 2002, Wang 2015, Woodward 2017; also Lewis 1986e, 237f. and 259f.) Many philosophers who reject modal realism have come to appreciate counterpart theory because of its explanatory and puzzle-solving power. We will give a few examples.