Isaiah Berlin in the context of "Moral universalism"

Negative liberty, or negative freedom, is freedom from interference by other people. Negative liberty is primarily concerned with freedom from external restraint and contrasts with positive liberty (the possession of the power and resources to fulfill one's own potential). The distinction originated with Bentham, was popularized by T. H. Green and Guido De Ruggiero, and is now best known through Isaiah Berlin's 1958 lecture "Two Concepts of Liberty".

Pluralism as a political philosophy is the diversity within a political body, which is seen to permit the peaceful coexistence of different interests, convictions, ideologies and lifestyles. While not all political pluralists advocate for a pluralist democracy, this is the most common stance, because democracy is often viewed as the most fair and effective way to moderate between discrete values.

Political theorist Isaiah Berlin, a strong supporter of pluralism, wrote: "let us have the courage of our admitted ignorance, of our doubts and uncertainties. At least we can try to discover what others ... require, by ... making it possible for ourselves to know men as they truly are, by listening to them carefully and sympathetically, and understanding them and their lives and their needs... ." Pluralism thus tries to encourage members of society to accommodate their differences by avoiding extremism (adhering solely to one value, or at the very least refusing to recognize others as legitimate) and engaging in good faith dialogue. Pluralists also seek the construction or reform of social institutions in order to reflect and balance competing principles.

British Jews (often referred to collectively as British Jewry or Anglo-Jewry) are citizens of the United Kingdom who are Jewish, forming one of the country’s oldest and most historically significant religious minority communities. Jewish presence in Britain dates to at least the 11th century, when William the Conqueror encouraged Jewish merchants and financiers to migrate from northern France to London. The Jews were expelled from England under Edward I in 1290, but a continuous community was re-established following the readmission of Jews under Oliver Cromwell in the 1650s. From the 18th century onwards, British Jews became increasingly integrated into national life, contributing to commerce, science, literature, and politics while maintaining distinctive religious and communal institutions. Some 60,000-70,000 British Jews served in the British Army during the Second World War, serving in all branches and theatres of war. Prominent British Jews have included Prime Minister Benjamin Disraeli; financier and activist Moses Montefiore; scientist Rosalind Franklin; playwright Harold Pinter; businessman Michael Marks; and philosopher Sir Isaiah Berlin.

Waves of migration from Eastern Europe in the late 19th and early 20th centuries transformed Jewish life in Britain, particularly in London’s East End, Manchester, and Leeds, substantially increasing the community's numbers while altering its cultural composition. The community has since diversified, including both long-established Anglo-Jewish families and more recent arrivals from Europe, the Middle East, and the Commonwealth.

"Two Concepts of Liberty" was the inaugural lecture delivered by the liberal philosopher Isaiah Berlin before the University of Oxford on 31 October 1958. It was subsequently published as a 57-page pamphlet by Oxford at the Clarendon Press. It also appears in the collection of Berlin's papers entitled Four Essays on Liberty (1969) and was reissued in a collection entitled Liberty: Incorporating Four Essays on Liberty (2002).

The essay, with its analytical approach to the definition of political concepts, re-introduced the study of political philosophy to the methods of analytic philosophy. It is also one of Berlin's first expressions of his ethical ontology of value-pluralism. Berlin defined negative liberty (as the term "liberty" was used by Thomas Hobbes) as the absence of coercion or interference with agents' possible private actions, by an exterior social body. He also defined it as a comparatively recent political ideal, which re-emerged in the late 17th century, after its slow and inarticulate birth in the ancient doctrines of Antiphon the Sophist, the Cyrenaic discipleship, and of Otanes after the death of pseudo-Smerdis. In an introduction to the essay, Berlin writes:

In ethics, value pluralism (also known as ethical pluralism or moral pluralism) is the idea that there are several values which may be equally correct and fundamental, and yet in conflict with each other. In addition, value-pluralism postulates that in many cases, such incompatible values may be incommensurable, in the sense that there is no objective ordering of them in terms of importance. Value pluralism is opposed to value monism, which states that all other forms of value can be commensured with or reduced to a single form.

Value-pluralism is a theory in metaethics, rather than a theory of normative ethics, or a set of values in itself. Oxford philosopher and historian of ideas Isaiah Berlin is credited with being the first to popularize a substantial work describing the theory of objective value-pluralism, bringing it to the attention of academia (cf. the Isaiah Berlin Virtual Library). The related idea that fundamental values can and, in some cases, do conflict with each other is prominent in the thought of Max Weber, captured in his notion of "polytheism".