Are complex phenomena “nothing but the sum of their parts”, or are they “more than the sum of their parts”? Physicists, chemists, and biologists as well as philosophers have long argued on both sides of this debate between the idea of reduction and that of emergence. At this point, argues Carl Gillett, the sides have reached a stalemate, where it is difficult to know in what ways the sides fundamentally disagree about the nature of the relation between a composite whole and its parts. In Reduction and Emergence in Science and Philosophy (Cambridge University Press, 2016), Gillett aims to break the stalemate by providing needed clarification about what divides contemporary reductionists from contemporary emergentists, and lays out the strongest positions on each side. Gillett, who is professor of philosophy at Northern Illinois University, uses his framework to provide a platform for future philosophical and scientific inquiry, helping reorient the debate towards fruitful empirical tests that might provide evidence for one view over the other, and point the way towards new issues regarding the nature of collectives.