The academic study of international relations (IR) has long been defined by theoretical pluralism, with scholars divided between competing perspectives. Core theories like realism, liberalism, and constructivism provide fundamentally different accounts of world politics. This theoretical diversity has advantages. Multiple paradigms allow creative debate and syntheses. However, theoretical pluralism also poses challenges. It can inhibit cumulative knowledge and fragment the field. This article examines the problem of pluralism in international relations theory: what are the sources of diverse theoretical perspectives, why does this diversity persist, and is theoretical pluralism beneficial or detrimental to the growth of IR as a field of study? It assesses debates over whether theoretical pluralism represents a strength or weakness for the development of international relations scholarship.
Sources of Theoretical Pluralism in International Relations
IR theory exhibits pluralism because different paradigms offer compelling but ultimately irreconcilable starting assumptions about human nature, the primacy of state vs. non-state actors, the role of material vs. ideational factors, and other issues. Core perspectives make simplifying assumptions that capture part of a complex reality. For instance, realism sees human nature as egoistic and conflictual, causing states to seek power and security. Liberalism assumes humans are capable of cooperation and traces conflict to skewed domestic politics. Constructivism grants ideas primacy over material forces in shaping interests and identities.
These foundational premises support coherent but divergent causal logics explaining international outcomes like war, cooperation, and change. The resulting theoretical perspectives are not commensurable on their own terms. As Sil and Katzenstein (2010) argue, paradigms rely on “analytical eclecticism” in how they select and synthesize assumptions from different social science disciplines. Their fundamental assumptions cannot be reconciled through empirical research alone. Competing theories persist because scholars approach IR with different philosophical, epistemological, and methodological commitments.
IR theory also fractured along various inter-paradigm debates. Realism split into classical and neo-variants over human nature assumptions. The inter-paradigm debate between realism and liberalism in the 1980s revolved around materialist vs. ideational explanations. More recent clashes pit rationalist approaches based on deductive logic against interpretivist methods reliant on inductive reasoning from history and discourse. These divides impede consolidation around a single theoretical framework.
Why Does Theoretical Pluralism Persist?
Theoretical diversity remains entrenched in IR for several reasons. First, given the enormous complexity of world politics, any single paradigm provides an incomplete picture. No theory can account for all states, issues, historical eras, and outcomes simultaneously with equal explanatory power. Reality is too multifaceted for unified theory. Second, research programs have built up immense intellectual capital around existing perspectives. Paradigms reproduce through doctoral training, conferences, and publications privileging certain assumptions. This institutionalization makes it difficult to displace dominant frameworks.
Third, theoretical progress depends on scholars creatively challenging and revising theories to overcome anomalies. Paradigms like realism evolve by absorbing and adapting concepts from rivals to explain new developments. Fourth, qualitative interpretivist and quantitative rationalist methodologies provide philosophically different but valid ways of acquiring knowledge. Methodological divisions reinforce theoretical pluralism. Finally, theory is shaped by contemporary political realities. New conditions like the end of the Cold War generate new theories, not consolidation. For these reasons, IR remains stuck between “multiparadigmatic eclecticism and incoherence” with no shared first principles (Sil and Katzenstein 2010, 411).
Benefits of Theoretical Pluralism
What are the benefits of this theoretical diversity that prevent IR from coalescing around a single paradigm? First, pluralism supports academic freedom and creativity. Different philosophical assumptions appeal to scholars with contrasting worldviews and interests. Consolidation around a narrow set of principles would impose intellectual conformity and stifle innovative theorizing. Second, theoretical debates drive conceptual and empirical progress as scholars refine arguments to respond to rivals. The clash between realism and liberalism since the 1980s generated vast literatures and advanced understanding of material and social dimensions of world politics.
Third, multiple perspectives reveal blind spots and hidden assumptions in dominant theories, improving explanatory power. Rising theories like constructivism and feminism expanded IR’s ontology beyond materialism. Fourth, diverse theories effectively explain different issue areas, eras, and actors. Realism benefits security studies, liberalism suits international political economy, and constructivism addresses identity and norms. Theoretical pluralism supports specialization and division of intellectual labor across subfields. Fifth, no single theory can encompass the scope and complexity of world politics across regions, cultures, and levels of analysis. Different analytical lenses are required to build holistic understanding.
In sum, theoretical pluralism promotes debate, creativity, intellectual progress, awareness of assumptions, specialized inquiry, and complex explanation. These benefits lead many to conclude diversity is integral to healthy scholarly discourse. Sil (2000) argues theoretical pluralism is “productive and constitutive of the discipline” (p. 328). Walt (1999) concludes it “contributes enormously to the vitality of the field” (p. 29). If theoretical uniformity was even possible, IR would lose its core strength—vibrant inter-paradigm debates propelling research.
Problems Posed by Theoretical Pluralism
However, other scholars argue extensive theoretical pluralism poses problems for IR as a field of study. First, theoretical fragmentation hinders accumulation of reliable, consistent knowledge. Individual studies situate findings within distinct paradigms using different concepts. This precludes systematically building on previous results towards explanatory closure. Second, incommensurable theories cannot be directly compared to determine which most accurately describes reality. Lack of shared standards for adjudicating scientific progress across paradigms allows poor explanations to persist.
Third, theoretical pluralism sustains academic tribalism where scholars rigidly defend “their” theory rather than seeking truth. This tribalism stifles honest debate, critique, and reformulation of assumptions. Fourth, the effort exerted attacking and defending theories against rivals diverts resources away from collective empirical research. Finally, extensive diversity without integration fails practitioners who seek usable guidance for policy and diplomacy. Watts (1996) concludes it leaves IR as an incoherent “‘patchwork quilt’ at best or an unpalatable ‘theoretical goulash’ at worst” (p. 29). From this view, diversity without synthesis impairs IR’s scientific enterprise and policy relevance.
Towards Theoretical Convergence and Coexistence
How can these tensions between the benefits and problems of theoretical pluralism be reconciled? Scholars propose resolving IR’s incoherence through two approaches—theoretical integration or bounded pluralism. The integrationist approach seeks to synthesize concepts and logics from different theories into coherent multi-causal frameworks. For instance, neoliberal institutionalism integrates realist assumptions about power politics with liberal arguments on how institutions mitigate anarchy. Bride and Groom (1998) similarly combine constructivist and rationalist approaches into a “conventional constructivism.” These syntheses identify complementary insights across paradigms.
However, Sil and Katzenstein (2010) counter that fundamental philosophical differences between research programs cannot be readily bridged at the theoretical level. Instead, they argue bounded pluralism focused on substantive dialogues around specific empirical issues will gradually generate some convergence and workable coexistence between theories. Rather than forcing synthesis, progress depends on identifying existing zones of agreement and scope conditions where certain theories have explanatory primacy. Exchanges in forums like the pages of International Organization contribute to this gradual theoretical rapprochement and refinement.
Conclusion
In conclusion, extensive theoretical pluralism poses both benefits and problems for international relations scholarship. Diversity promotes academic freedom, debate, and specialized inquiry but risks incoherence and fragmentation. Efforts to forcibly integrate IR theory fail due to incommensurable philosophical assumptions embedded in dominant paradigms. However, through substantive dialogues on shared issues and empirical puzzles, some intellectual convergence and cooperation between research programs may emerge. Ultimately, theoretical pluralism in IR seems unavoidable and productive but needs bounding to enable cumulative knowledge. This requires not imposing uniformity but seeking shared understanding of how, where and why different theories provide unique and partial insights into the complex reality of world politics.
References
Bride, T. M., & Groom, A. J. (1998). International Relations: A Handbook of Current Theory. Lynne Rienner Publishers.
Sil, R., & Katzenstein, P. (2010). Beyond Paradigms: Analytic Eclecticism in the Study of World Politics. Palgrave Macmillan.
Sil, R. (2000). The Foundations of Eclecticism: The Epistemological Status of Agency, Culture, and Structure in Social Theory. Journal of Theoretical Politics, 12(3), 353-387.
Walt, S. (1999). One World, Many Theories. Foreign Policy, (110), 29-46.
Watts, M. (1996). International Relations or Internecine Relations? Review of International Studies, 22(1), 29-44.
