Religion

There is no consensus on the definition of religion (Clarke & Beyer, The World's Religions, Routledge, 2009, page 136). Traditional definitions have tended to try to formulate the "western folk conception" of religion, i.e. the rather vague ideas ordinary westerners have of what religion is, based on their experience of religion in the west. As long ago as 1912, Leuba (Psychology of Religion) listed 50 different definitions, and many more have been suggested since. Most observers classify academic definitions into two types:

1. substantive definitions, which try to define what religion "is"; most of these define it in terms of relation to the supernatural
2. functional definitions, which try to define religion by the role it plays in the lives of individuals and/or societies

The former have been criticized as being too narrow: for example, some of them would exclude Buddhism, which most people regard as a religion. The latter, on the other hand, have been criticized as too broad, allowing all sorts of things to be regarded as some people's "religion": sport, art, politics, drugs etc.

More recently, some scholars have argued that, rather than a single characteristic or group of characteristics, Wittgenstein's family resemblance approach should be adopted to the definition of religion. As members of a family resemble each other in various ways, though there is no one characteristic or group of them that defines membership in the family, so a religion should be defined as something that has most, but not necessarily all, of a list of characteristics. A variety of such lists have been proposed by scholars.

Classification of religions

Religions have been classified in a variety of ways.

Normative

Normative classifications are those developed within particular religious traditions, which tend to classify other religions by how far they agree or disagree with the classifying tradition.

Geographical

These classifications classify religions by where they are found, or where they originated, or a mixture of the two.

Ethnographic/linguistic

These systems classify religions by the racial and/or linguistic groups in which they evolved. For example, Duren Ward's 1909 classification:

1. Oceanian
2. African
3. American (Indian)
4. Mongolian
5. Mediterranean
   • Semitic
   • Aryan

Philosophical

Pfeiderer classified religions by the balance between dependence and freedom (listing from the most dependence-emphasizing):

• ancient Semites, Egyptians, Chinese
• Brahminism and Buddhism
• Islam
• Christianity
• Judaism
• Zoroastrianism
• Indians, Germans, Greeks, Romans

He regarded Christianity as the most balanced.

Morphological

A major classification of this type is that into ethnic religions and universal religions. Sometimes a third group is added, called segmental religions.

1. ethnic religions: Hinduism, Judaism, Shinto, tribal religions, etc.
2. universal religions: Buddhism, Christianity, Islam
3. segmental religions: Sikhism, Jainism, Cao Dai

A classification that works out about the same as some versions of this is into religions founded by particular individuals at particular points of time and those that simply evolved.

Also in this category is Tielen's classification:

• nature religions
• ethical religions

Phenomenological

A major example of this is van der Leeuw's classification:

1. religions of remoteness and flight: Confucianism and Deism
2. religions of style: Zoroastrianism
3. religions of strain and form: Greek
4. religions of infinity and asceticism
5. religions of nothingness and compassion: Buddhism
6. religions of will and obedience: Judaism
7. religions of majesty and humility: Islam
8. religions of love: Christianity

History

Until around three millennia ago, religion was inseparable from ethnicity. Each ethnic group had its own religion. If you belonged to one you belonged to the other. Most of these ethnic religions have now died out, and most of the others are in serious decline, though Hinduism and Judaism are very much alive.

The first "new" religion to be founded seems to have been Zoroastrianism, which became a major religion for some time, but declined and now survives on a very small scale. The same pattern holds for Jainism. Manichaeism became a major religion but died out altogether a few centuries ago. Mandaeanism never became a major religion, but still survives on a small scale. More than half the world's population now belongs to just three religions founded a couple of millennia ago: Buddhism, Christianity and Islam.

Starting with Sikhism, a very large number of new religions have been founded in the last few centuries, most of which sank without trace. It was estimated in 2002 that there were 9900 religions, with 2 or 3 more founded every day.

In the twentieth century, substantial numbers of people abandoned religion altogether.