Criticism of religion involves criticism of the validity, concept, or ideas of religion.
Historical records of criticism of religion go back to at least 5th century BCE in ancient Greece, in Athens specifically, with Diagoras "the Atheist" of Melos. In ancient Rome, an early known example is Lucretius' De rerum natura from the 1st century BCE.
Every exclusive religion on Earth (as well as every exclusive world view) that promotes exclusive truth-claims necessarily denigrates the truth-claims of other religions. Thus, some criticisms of religion become criticisms of one or more aspects of a specific religious tradition.
Critics of religion in general may view religion as one or more of: outdated, harmful to the individual, harmful to society, an impediment to the progress of science or humanity, a source of immoral acts or customs, a political tool for social control.
Definition of religion
Religion is a modern Western concept that developed from the 17th century onwards, not before. For example, in Asia, no one before the 19th century self-identified as a "Hindu" or other similar identities. The ancient and medieval cultures that produced religious texts, like the Hebrew Bible, New Testament or the Quran, did not have such a conception or idea in their languages, cultures, or histories and neither did the peoples in the Americas before Columbus.
Today, even though modern researchers conceive religion broadly as an abstraction which entails beliefs, doctrines and sacred places, there is still no scholarly consensus over what a religion is.
History of criticism
In his work De rerum natura, the 1st-century BCE Roman poet Titus Lucretius Carus wrote: "But 'tis that same religion oftener far / Hath bred the foul impieties of men". A philosopher of the Epicurean school, Lucretius believed the world was composed solely of matter and void and that all phenomena could be understood as resulting from purely natural causes. Despite believing in gods, Lucretius, like Epicurus, felt that religion was born of fear and ignorance, and that understanding the natural world would free people of its shackles. He was not against religion in and of itself, but against traditional religion which he saw as superstition for teaching that gods interfered with the world.
During the Islamic Golden Age, philosopher Al-Ma'arri criticized all prophets' statements as fabrications, and branded God in Islam a hypocrite for forbidding murder but sending angels to take each man's life.
At the beginning of the 16th century, Niccolò Machiavelli said: "We Italians are irreligious and corrupt above others... because the church and her representatives have set us the worst example". To Machiavelli, religion was merely a tool, useful for a ruler wishing to manipulate public opinion.
In the 18th century, the French Enlightenment philosopher Voltaire was a Deist and strongly critical of religious intolerance. Voltaire complained about Jews killed by other Jews for worshiping a golden calf and similar actions; he also condemned how Christians killed other Christians over religious differences and how Christians killed Native Americans for not being baptised. Voltaire claimed the real reason for these killings was that Christians wanted to plunder the wealth of those killed. Voltaire was also critical of Muslim intolerance towards other religions. Also in the 18th century, the Scottish Enlightenment philosopher David Hume criticised the teleological arguments for religion. Hume claimed that natural explanations for the order in the universe were reasonable. An important aim of Hume's writings was demonstrating the unsoundness of the philosophical basis for religion.
The 18th-century American Enlightenment political philosopher and religious skeptic Thomas Paine is especially noteworthy both for his contributions to the cause of the American Revolution and his writings in defense of Deism alongside the criticism of Abrahamic religions. In The Age of Reason (1793–1794) and other writings he advocated Deism, promoted reason and freethought, and argued against institutionalized religions in general and the Christian doctrine in particular.
