Scientific conflicts often stem from differences in the conceptual framework through which scientists view and understand their own field. In this chapter, I analyze the ontological and methodological assumptions of three traditions in evolutionary biology, namely, Ernst Mayr’s population thinking, the gene-centered view of the Modern Syn thesis, and the Extended Evolutionary Synthesis. Each of these frameworks presupposes a different account of "evolutionary causes," and this discrepancy prevents mutual understanding and objective evaluation in the recent contention surrounding the EES. From (...) this perspective, the chapter characterizes the EES research program as an attempt to introduce causal structures beyond genes as additional units of evolution, and compares its research methodology and objectives with those of the traditional MS framework. (shrink)