Superstition is a belief in supernatural causality: that one event leads to the cause of another without any physical process linking the two events, such as astrology, omens, witchcraft, etc. that contradicts natural science. Opposition to superstition was a central concern of the intellectuals during the 18th century Age of Enlightenment. The philosophes at that time ridiculed any belief in miracles, revelation, magic, or the supernatural, as "superstition," and typically included as well much of Christian doctrine. The word is often used pejoratively to refer to religious practices other than the one prevailing in a given society, although the prevailing religion may contain just as many supernatural beliefs. It is also commonly applied to beliefs and practices surrounding luck, prophecy and spiritual beings, particularly the belief that future events can be foretold by specific unrelated prior events.