IrreligionIrreligion is the neglect or active rejection of religion and, depending on the definition, a simple absence of religion. Irreligion takes many forms, ranging from the casual and unaware to full-fledged philosophies such as atheism and agnosticism, secular humanism and antitheism. Social scientists tend to define irreligion as a purely naturalist worldview that excludes a belief in anything supernatural. The broadest and loosest definition, serving as an upper limit, is the lack of religious identification, though many non-identifiers express metaphysical and even religious beliefs.
Naturalism (philosophy)In philosophy, naturalism is the idea or belief that only natural laws and forces (as opposed to supernatural ones) operate in the universe. According to philosopher Steven Lockwood, naturalism can be separated into an ontological sense and a methodological sense. "Ontological" refers to ontology, the philosophical study of what exists. On an ontological level, philosophers often treat naturalism as equivalent to materialism. For example, philosopher Paul Kurtz argues that nature is best accounted for by reference to material principles.
FreethoughtFreethought (sometimes spelled free thought) is an epistemological viewpoint which holds that beliefs should not be formed on the basis of authority, tradition, revelation, or dogma, and that beliefs should instead be reached by other methods such as logic, reason, and empirical observation. According to the Oxford English Dictionary, a freethinker is "a person who forms their own ideas and opinions rather than accepting those of other people, especially in religious teaching.
History of atheismAtheism, in the broadest sense, is an absence of belief in the existence of deities. In a narrower sense, atheism is specifically the position that there no deities and any statements to the contrary are false ones. The English term 'atheist' was used at least as early as the sixteenth century and atheistic ideas and their influence have a longer history. In the East, a contemplative life not centered on the idea of deities began in the sixth century BCE with the rise of Indian religions such as Jainism, Buddhism, various sects of Hinduism in ancient India, and of Taoism in ancient China.
Nontheistic religionNontheistic religions (not to be confused with atheism) are traditions of thought within a religious context—some otherwise aligned with theism, others not—in which nontheism informs religious beliefs or practices. Nontheism has been applied and plays significant roles in Hinduism, Buddhism, and Jainism. While many approaches to religion exclude nontheism by definition, some inclusive definitions of religion show how religious practice and belief do not depend on the presence of a god or gods.
TheismTheism is broadly defined as the belief in the existence of at least one deity. In common parlance, or when contrasted with deism, the term often describes the classical conception of God that is found in monotheism (also referred to as classical theism) — or gods found in polytheistic religions — a belief in God or in gods without the rejection of revelation as is characteristic of deism. Gnosticism is the belief in personal spiritual knowledge. Atheism is commonly understood as non-acceptance or rejection of theism in the broadest sense of theism, i.