Most textbooks on the international relations (IR) characterize liberalism as one of the main theoretical schools of the IR field—typically alongside realism and perhaps some other less mainstream approaches like international society, Marxism, constructivism, or feminism. As such, liberalism is commonly considered to be the main competing theoretical approach to the dominant IR theory of realism. The frequent comparisons made between realism and liberalism in the IR literature typically entail realism advancing a pessimistic view of human nature, versus the more optimistic view espoused by liberalism. Realists therefore see conflict as the norm in international affairs, while liberals are more hopeful about the prospects for peace and international cooperation. Realists seek to explain international politics by examining state-to-state relations within an anarchical system of mutual distrust and suspicion, while liberals consider other international actors, as well as actors and institutions within the state, as the underlying causes of a more interdependent and law-governed world. This broad understanding of liberalism represents the approach as it has developed throughout the post-World War II era. Although contemporary liberal theory can be divided into different strands, which this chapter discusses in a following section, the notion of idealism as it pertains to IR is a slightly different and older idea that played an important role in the evolution of what is now recognized as contemporary liberal IR theory
Comparison
The Realism is a philosophy that understands the world as relational, causality as contingent, and knowledge as socially produced. It gained prominence in geography during the 1980s as an analytical framework for thinking about and “practicing” both social science (critical realism) and natural science (transcendental realism). This distinction between the social and natural sciences is inherent to a realist separation between natural and social “kinds”: Society is recognized as an open system that can never replicate the closed conditions of a laboratory, and institutions and actors are understood to be in a constant state of flux as compared with the more intransitive physical phenomena of the natural world. This is consonant with a realist ontology, which posits the existence of a reality outside human consciousness that is independent of the social construction of nature. As an epistemology, realism asserts that we can actually know something about this world beyond our cognition of it.
On the other hand, the term liberalism has a variety of meanings that are difficult to pin down. Political theorists view liberalism as “a complex of doctrines, ideals, suggestions for implementing those ideals, beliefs, and informal patterns of habitual action and thought”. For purposes of simplification, liberalism can be defined as a political doctrine associated with the concerns of protecting individual rights and liberties; tolerating diverse opinions, cultures, values, and practices; resolving disagreements through bargaining rather than coercion; and guaranteeing collective equality while minimizing public interference with individuals' autonomy. In varying degrees, the elevation of individual rights and self-development inherent in liberalism is at cross-purposes with the sense of community. Liberals answer this charge by noting that individual rights and liberties are not ...