Atheism is the philosophical position that either affirms the nonexistence of gods or rejects theism. In its broadest definition, atheism is the absence of belief in deities, sometimes called nontheism. Although atheists are commonly assumed to be irreligious, some religions, such as Buddhism, have been characterized as atheistic. Many self-described atheists share common skeptical concerns regarding supernatural claims, citing a lack of empirical evidence for the existence of deities. Other arguments for atheism are philosophical, social or historical. Although many self-described atheists tend toward secular philosophies such as Humanism, rationalism, and naturalism, there is no one ideology or set of behaviors to which all atheists adhere. The term atheism originated as a pejorative epithet applied to any person or belief in conflict with established religion. With the spread of freethought, scientific skepticism, and criticism of religion, the term began to gather a more specific meaning and was sometimes used as a self-description by atheists.