ISMs matter. They reflect underlying philosophical points of departure and are rooted in specific explicit assumptions about how the world works. The very different expectations and conclusions of diverse theories often stem from the fact that those theories were derived from distinct and contrasting paradigmatic roots. To be aware of those foundations is to understand the likely strengths, weaknesses, limitations, controversies, and specific attributes of the various theories. In contemporary international relations (IR) scholarship there is a common claim that we are past paradigms, and many younger scholars are expected to recite this mantra. But making such a claim is a political act, not an intellectual one. It reflects the hegemony of one particular paradigmatic perspective—one with specific analytical building blocks of individualism, materialism, and hyperrationalism—an approach that is a paradigm and one so powerful that it has been described as an “intellectual monoculture.”