In this paper we explore Jaegwon Kim’s principle of explanatory exclusion. Kim’s support for the principle is clarified and we critically evaluate several versions of the dual explananda response authors have offered to undermine it. We argue that none of the standard versions of the dual explananda reply are entirely successful and propose an alternative approach that reveals a deep tension in Kim’s metaphysics. We argue that Kim can only retain the principle of explanatory exclusion if he abandons his longstanding critique of nonreductive physicalism.