Drawing on the work of Michael Freeden, Edwin van de Haar argues that supporters of liberty only really require three labels.

Dr Edwin van de Haar specializes in the liberal tradition in (international) political theory. He has lectured political theory and international relations at Brown University, Leiden University and Ateneo de Manila University. This article is based on his new book Degrees of Freedom. Political Philosophy and Ideology (Transaction Publishers, April 2015). Earlier he wrote Classical Liberalism and International Theory. Hume, Smith, Mises and Hayek (2009), as well as a number of chapters and articles on the wider liberal tradition in international political theory.

Liberalism as a political idea has become far too complicated. It appears there are as many liberalisms as there are liberals. To name just a few: libertarianism, classical liberalism, bleeding heart liberalism, economic liberalism, political liberalism, social liberalism, high liberalism, minarchism, objectivism, anarcho‐​capitalism, and of course neoliberalism. In international relations theory you can also find neoliberal institutionalism, liberal internationalism or embedded liberalism, while no doubt additional liberalisms can be found in other academic subjects. Clearly this all amounts to an incomprehensible liberal mess, which needs to be sorted out.

Getting a decent grasp of liberal political thought does not have to be this complicated. As a rule of thumb you only need to keep in mind one of the perennial questions in political philosophy: what is the just relation between the individual and the state? Roughly, there are three liberal answers: the state should have (almost) no role in individual life, the state should have a limited role, or the state should have a fairly large role. The liberal variants that are associated with these answers are libertarianism, classical liberalism and social liberalism, respectively. To be sure, these three are not fully mutually exclusive, and the thinkers associated with the variants do not always neatly fit the categorization, certainly not over their whole writing careers. Still, this divide into three is much better than the alternatives, including the grouping of classical liberalism and libertarianism under one libertarian label, which is unfortunately also the case at this great website!

Conceptual Approach

The divide‐​into‐​three rule of thumb mentioned above remains valid after more elaborate analyses of liberalism, based on the writings of the British political theorist Michael Freeden. Put briefly, Freeden argues that every political ideology should be seen as a framework composed of a number of political concepts. These concepts vary in importance while their meaning is contested within the ideology. It is possible to distinguish core, adjacent and peripheral concepts, which together make a unique set of political ideas. While some of the individual concepts overlap, there is significant variation between the frameworks. This enables the distinction between different liberal variants, which are still part of the larger liberal family.

For example, the concept of liberty is key to all liberal variants, but liberty has different meanings. Isaiah Berlin’s famous divide between positive and negative liberty is relevant here. The latter can be defined as “the freedom from interference by others,” the first “the freedom to fully enjoy one’s rights and liberties,” which often demands some support of the state. Classical liberalism is associated with the negative conception and social liberalism with the positive meaning. Yet the meaning of negative liberty may be further contested. The protection from interference by others may be taken as absolute, which is far more stringent than the classical liberal interpretation, which does allow for compulsory taxation of individuals to pay for public services. Now we are entering the libertarian domain, which is in itself divided into those who hold an absolute idea of negative liberty (the anarcho‐​capitalists), and those who permit a minimal infringement of property rights to pay for police, external defense and the judiciary (the minarchists). This is also why conservatism is not as closely related to the liberal family as sometimes thought. For conservatives, individual liberty is not a core concept at all. Much more can be said about this, but the example shows that political concepts are core to political ideas, but that these concepts never just have one uncontested meaning. Analysis at a deeper level is a prerequisite for the understanding of political ideology.

In this context it is disappointing that Freeden concentrates on domestic politics (as has academic political theory traditionally done) while it is as important to include ideas about international affairs. After all, foreign affairs are an important driver of political policies, and also of domestic change. The differences between liberal ideas in domestic politics are also clearly visible and ideologically consistent in their view on international affairs. For example in the role of the nation in individual life and in global politics, the perennial question in liberal debate whether free trade fosters international peace, or the alleged usefulness of international governmental organizations.

Morphological Framework

The liberal ideological framework of concepts (or “morphological framework” in the words of Freeden) is presented below. For the sake of clarity, the international aspects are presented separately, also because they are less clearly recognized as proper concepts as of yet. A comparison with conservatism is added because the differences between liberalism and conservatism are sometimes erroneously seen as negligible. Surely, some of the concepts and their distribution over the liberal variants and conservatism will raise questions. These cannot all be answered here; most are addressed in my book Degrees of Freedom: Liberal Political Philosophy and Ideology. However, a number of short clarifying comments are given below the tables.

Table 1: The Morphology of Liberalism and Conservatism

Libertarianism Conservatism
Negative freedom, realistic view of human nature, spontaneous order, limited state Positive freedom, positive view of human nature, social justice as self‐​development, extended state Negative freedom, realistic view of human nature, spontaneous order, natural law including strict defense of property rights Realistic view of human nature, organic change, human order with “extra‐​human” origins, counter movement
Adjacent concepts Natural law, rule of law/​constitutionalism Modern human rights, rule of law and neutral state, social contract (Mill: utilitarianism) Minarchism: minimal state, rule of law Groups/​family, hierarchy, active state, sometimes: spontaneous order
Peripheral concepts Social justice, strict defense of property rights, democracy, utilitarianism Property rights, spontaneous order Social justice Individual (property) rights, freedom

Source: Edwin van de Haar, Degrees of Freedom. Liberal Political Philosophy and Ideology(Transaction Publishers, 2015).

Table 2: Liberalism, Conservatism and International Relations

Libertarianism Conservatism
Nation as limit of individual sympathy Yes No No Yes
State as prime actor in world politics Yes No No Yes
International governmental
No Yes No No
Can war be eliminated? No Yes Yes No
Does trade foster peace? No Yes Yes No

Source: Edwin van de Haar, Degrees of Freedom. Liberal Political Philosophy and Ideology (Transaction Publishers, 2015).

Classical Liberalism

Classical liberalism originates from the eighteenth century Scottish Enlightenment, especially in the writings of David Hume and Adam Smith. It is also associated with thinkers such as Ludwig von Mises, Friedrich Hayek, Milton Friedman and James Buchanan. Classical liberalism has a realistic view of human nature, which means that man is seen a mix of rationality and emotion, so humans are not guided by reason alone. Individual freedom is the main classical liberal goal and it is best preserved by protecting classical human rights, the rule of law, and reliance on spontaneous ordering processes in society, such as the free market. The classical liberal state is limited, which means it has to perform or arrange for a number of important public tasks and services. Besides defense, police, and judiciary, this includes a minimal amount of welfare arrangements, some environmental regulation, or other public goods that cannot be dealt with through markets. Classical liberals have thus far been unable to be define their limited state with precision, although it is clear is significantly smaller than those of the social liberals. In international affairs, classical liberals see the world as a society of nation states. The nation is the “outer limit” of meaningful human sympathy. World peace is untenable and free trade, while desirable for many reasons, cannot change that. Consequently, international relations has to deal with the inevitable occurrence of war and conflict, with the balance of power as the spontaneous ordering mechanism in the international realm. International governmental organizations are often just as bad as big states are in the domestic situation.


Like social liberalism, libertarianism originates from the nineteenth century, for example in the writings of Lysander Spooner, Herbert Spencer and William Graham Sumner. Libertarians criticize classical liberals for allowing the state to grow too large. Instead, the strict protection of individual natural rights to life, liberty, and property ensures a just society. Significant traces of natural law thinking can also be found in classical liberalism, but the classical liberals justify more infringements of property rights. Through taxation but also different kinds of regulation, not least the state monopoly in monetary matters. Libertarians favor a system where free people will be able to use their talents and cooperate in strictly voluntary ways. Some, like Murray Rothbard or Hans‐​Hermann Hoppe, argue this society can totally rely on spontaneous order for the provision of all necessary services and therefore want to abolish the state completely. Others, such as Ayn Rand, think there is a need to publicly organize defense, police, and judiciary. No libertarian thinks there is a need for a centrally organized redistribution of resources, for example to advance ideas of social justice. Instead they rely on spontaneous forces to assist disadvantaged people in society. There is no such thing as a stable nation state, as secession is a rightful way for people to form new political entities. In the international domain libertarians are isolationists; only when people leave each other alone is international peace fostered, just as through free trade. Of course, in a stateless world, there is also no room for international governmental organizations. Ayn Rand is the hawkish exception here. At the same time, most libertarians emphasize they are not pacifist, demanding a strong defense in case of foreign invasion.

Social Liberalism

Social liberals are liberals in the contemporary American sense. Social liberal thought originates in the writings of John Stuart Mill and his successors labeled the New Liberals. Since the 1970s John Rawls and his followers have been the major sources of intellectual inspiration. For social liberals the libertarian and classical liberal ideas allow a world full of social injustice. Individuals need to have the capacity to develop their talents, and should be able to learn skills and get the right knowledge to use their natural talents in the labor market and elsewhere. They also need to be able to fully participate in democratic decision‐​making processes. Otherwise the idea of liberty is just formal and without much practical meaning. This concern for social justice entails the redistribution of income to ensure widely‐​accessible education and a welfare system (social security, public health) that takes care of the less fortunate. This leads to a much bigger role for the state, and a bigger tax bill, than in the other two liberalisms. Social liberals do not think spontaneous ordering forces suffice to bring these requirements about. Their positive view of human nature means they think reason can in the end overcome the emotions. This leads to a trust in rationally constructed public arrangements, which also shows in their views on international relations. Peace is possible because people will be able to see that war is bad. International organizations and international law are able to redirect violence to the negotiating tables, ultimately leading to a peaceful world. The ideals of a completely stateless society, or perhaps a world federation, also figures prominently in social liberal international thought.

Liberalism and Conservatism

In an essay focusing on the liberal differences it would be silly to present conservatism as a unified ideology. Therefore for purposes of comparison only mainstream conservatism is presented here, as found in the writings of Edmund Burke, Alexis de Tocqueville and Lord Acton, Roger Scruton’s The Meaning of Conservatism, Robert Nisbet’s Conservatism, or Russel Kirk’s The Conservative Mind. This means that American neoconservatism is left aside here.

The main differences between conservatism and liberalism are that conservatives do not value individual liberty as such. These are peripheral concepts at best, certainly concerning non‐​economic or immaterial issues. This can partly be explained by the larger influence of religious views in conservatism, for example on issues such as abortion, gay rights, euthanasia, et cetera. Conservatives do not hesitate to use state power to regulate or prohibit such issues, while these fall within the individual private sphere for all three liberal variants. This is not to say that religion and liberalism do not go together, only that for liberals religion should remain private, whereas conservatives draw religious issues into the public sphere.

Conservatives tend to have the same view of human nature as classical liberals and libertarians, and often find themselves in agreement with them on economic issues. Conservatives are not defenders of the status quo, but favor slow organic change, that does not suddenly overturn the societal order which is the result of “the wisdom of the ages.” This is not unlike Popper’s piecemeal engineering so beloved by Hayek, but the difference is that all liberals, classical liberals included, are optimistic about the effects of technological change and scientific innovation. Conservatives also tend to be a counter‐​movement: when there is a left majority they lean to the right, but also vice versa. In the latter situation conservatives will not be strong defenders of individual property rights. Only classical liberals and conservatives (again, note this excludes the neocons) have identical, realistic ideas about international relations.


This essay is just meant to whet the appetite of the readers, rather than to present a full picture of the differences and similarities within liberalism, and between liberals and conservatives. It is an attempt to show that a number of ideational divides within liberalism are real, but this should not be made as complex as is often done. The morphological approach shows that a divide in three liberal variants suffices to include all main ideas and main thinkers, from the liberal origins to the present, on domestic and international politics. It also clarifies the differences with conservatism, or other ideologies for that matter. The essay is a call upon liberals and other writers to keep it simple and to stop making up all kinds of liberalisms, which are hard to understand. This practice has not been good for the appeal of liberalism. That is perhaps the biggest shame, as liberal ideas offer many great choices for all people, everywhere on the globe.