Western culture is characterized by a host of artistic, philosophic, literary and legal themes and traditions; the heritage of Greek, Roman, Germanic, Celtic, Slavic and other ethnic and linguistic groups. Christianity including the Roman Catholic Church, Protestantism and the Orthodox Church, has played a prominent role in the shaping of Western civilization since at least the 4th century as did Judaism (particularly Hellenistic Judaism and Jewish Christianity). Before the Cold War era, the traditional Western viewpoint identified Western civilization with the Western Christian (Catholic-Protestant) countries and culture.
A cornerstone of Western thought, beginning in ancient Greece and continuing through the Middle Ages and Renaissance, is the idea of rationalism in various spheres of life, especially religion, developed by Hellenistic philosophy, scholasticism and humanism. The Catholic Church was for centuries at the center of the development of the values, ideas, science, laws and institutions which constitute Western civilization. Empiricism later gave rise to the scientific method during the scientific revolution and the Enlightenment. Values of Western culture have throughout history been derived from political thought, widespread employment of rational argument favouring freethought, assimilation of human rights, the need for equality and democracy.
Ancient Greece is considered the birthplace of many elements of Western culture, with the world's first democratic system of government and major advances in philosophy, science and mathematics. Greece was followed by Rome, which made key contributions in law, government, engineering and political organization. Western culture continued to develop with the Christianisation of Europe during the Middle Ages and the reform and modernization triggered by the Renaissance. The Church preserved the intellectual developments of classical antiquity and is the reason many of them are still known today. Medieval Christianity created the modern university, the hospital system, scientific economics, natural law (which would later influence the creation of international law) and numerous other innovations across all intellectual fields. Christianity played a role in ending practices common among pagan societies, such as human sacrifice, slavery, infanticide and polygamy. The globalization by successive European colonial empires spread European ways of life and European educational methods around the world between the 16th and 20th centuries. European culture developed with a complex range of philosophy, medieval scholasticism and mysticism and Christian and secular humanism. Rational thinking developed through a long age of change and formation, with the experiments of the Enlightenment and breakthroughs in the sciences. Tendencies that have come to define modern Western societies include the concept of political pluralism, prominent subcultures or countercultures (such as New Age movements) and increasing cultural syncretism resulting from globalization and human migration.
The West as a geographical area is unclear and undefined. More often a country's ideology is what will be used to categorize it as a Western society. There is some disagreement about what nations should or should not be included in the category and at what times. Many parts of the Eastern Roman Empire are considered Western today but were Eastern in the past. Geographically, the "West" of today would include Europe (especially the European Union countries) together with extra-European territories belonging to the English-speaking world as well as the Hispanidad, the Lusosphere or the Francophonie in the wider context. Since the context is highly biased and context-dependent, there is no agreed definition what the "West" is.
It is difficult to determine which individuals fit into which category and the East–West contrast is sometimes criticized as relativistic and arbitrary. Globalism has spread Western ideas so widely that almost all modern cultures are, to some extent, influenced by aspects of Western culture. Stereotyped views of "the West" have been labeled Occidentalism, paralleling Orientalism—the term for the 19th-century stereotyped views of "the East".