What we refer to as the religion of Druidism is a very complex subject, usually broken into three stages:
The advent of neodruidism, sometimes called Reform Druidism, was actually a joke--a protest against Minnesota's Carleton College, which had a requirement that all students attend a worship service once a week. In 1963, a group of students who had no interest in religion decided to test this, and claimed to be the Reformed Druids of North America. They held services on Sunday, combining prayers to Mother Earth, Celtic deities, meditation, Zen, Christian mystical writings, and their own philosophies. The university accepted this, to their surprise. More to their surprise, they continued the group, finding that they were actually getting something out of it.
Upon setting up a chapter in Berkeley, the NRDNA--New Reformed Druids of North America--was formed, taking a less mesodruidic stance; i.e. less a mishmash of philosophies and more concerned with scholarship. However, even this distinction isn't quite correct, as the philosophy of Reformed Druidism is kept intentionally vague--namely, the Earth is Good, and nature has a polarity, but not a duality. Thus, there are NRDNA groups which mix this philosophy and many other religions--Buddhism, Christianity, Judaism, Wicca, and so on.
From the RDNA, two groups were formed: Ar nDraiocht Fein, which is primarily concerned with reconstructing an Indo-Eurpean religion; and the Henge of Keltria, which is strictly Celtic in its interest. The reason for this was the lack of organization or even theology in the RDNA. In 1983, Issac Bonewits led an offshoot dedicated to reconstructing an Indo-European priesthood through studying the works of Stuart Piggot, Georges Dumezil, and other archaeologists and anthropologists. The intent was not Pan-Celtic, but Pan-European, based on the belief that the paleodruids (among many other groups, but the druids being the most recognizable) were the last vestiges of a neolithic/Bronze Age priesthood that existed throughout Europe.
In 1986, five members of ADF taped a list of concerns to Bonewits' van door--a self-conscious mimicking of Martin Luther. They felt that Druidism was a specifically Celtic priesthood/religion and not a pan-European one. Frustrated, they split off into their own group, the Henge of Keltria, led by Tony and Pat Taylor. The Henge's focus is to restore as much as possible of the original, classical druidism, though with a modern sensibility (hense no sacrifices of animals or humans, but things like a revival of the mistletoe rite described by Pliny).
What is most important, however, about both branches (and many other, smaller branches) of neodruidism is a belief in the sacredness of the earth, the multiplicity of divinities, and the celebration of the Eightfold Year. Unlike some mesodruidic groups, they do not discriminate because of gender; sexuality is left open to the individual (which, given what is known of the Celts, is rather appropriate), and they have thrown out many of the misconceptions of the mesodruids and replaced them with sound scholarship. Some branches believe in magic, while others only in ritual and worship. The ADF has an archdruid at their head, while the Henge has a president. What is at the core, however, is always the same--seeking wisdom from nature, doing no harm, and worshipping the gods. (For more on each group, see sleeping wolf's w/u's on them.)
It should also be mentioned that there is one more variation, one which is not usually explored or written about, namely Celtic Reconstructionism. While ADF and the Henge refer to Druidism, there are some neodruids who do not take the title "Druid" as they feel they cannot replicate the original, paleodruidic priesthood. Instead, they call their religion Celtic Reconstructionism, so as to acknowledge the lack of true druids as existed in the classical period. (I have to say, I agree with them, in their eschewing the term "Druidism" as inaccurate--however, it is the most convenient term, the one most people are familiar with.)
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