The article aims at contributing to philosophical understanding of issues in international political economy (IPE). The philosophical formations of different approaches to conducting research in IPE demonstrate that all its divisions are conditional, with permeable rather than impenetrable boundaries. To simplify introduction, some IPE textbooks follow Robert Gilpin’s “trichotomous categorisation”, or theoretical division of the field into realism, liberalism and Marxism/structuralism, which fails to clearly define cultural and historical roots, ignores alternative philosophical approaches to IPE, and denies the possibility of theoretical mergers. With the main focus on the notion of power, this article aims at exploring the possible ways to overcome this trichotomous theoretical division, making the attempt to find ground for theoretical merger. The paper concludes that the theoretical boundaries can be transcended by merging different concepts (a “horizontal” merger), or by approaching the same phenomena in different epistemological ways (a “vertical” merger).