(To part 3)
The Greco-Roman historian and geographer Strabo (63 BC), who had travelled extensively and was well informed, reports that there were three forms of spiritual leadership among the Celts. First the Druids, second the Bards and third the Vates.
The word 'druid' is derived from the Greek word 'oak' and the oak was revered as a sacred tree by the Druids. However, the Gaelic word is 'druidh' and that means a wise man or magician. Both meanings already indicate that the culture of the Druids was special.
In Greek, oak is 'drus'. That is why some historians believe that this is where the name 'druid' comes from, because the oak was the most important tree among the Celts.
The worship of the oak is based on a legend. The oak was the first tree to be created and from this tree man arose. From this fact we can make a comparison with the root fire or the number 1, which connects above and below. From such a connection the divine man will one day arise.
The fact that the mistletoe that grows on the oak never loses its leaves indicates its eternity from the so-called root fire: it was, is and will be. The root fire originates from the spinal cord and has to be drawn upwards.
The story that Abraham received the angel of Jehovah under the branches of the oak means that his state of consciousness was in harmony with the sacred root fire that had sprung up in his spinal cord. That fire reached up to his head, for Abraham received the angel under the branches of the oak.
Roman writers such as Pliny and Julius Caesar provide much information about the Celts.
The Druids, as the Magi among the Gauls are called, held nothing more sacred than the mistletoe and the tree that bore it, the oak. Only for this reason did they choose the oak groves and perform no rite without a branch of this tree being present .
Therefore, we can now better understand what it must have meant for the population that entire oak forests were destroyed. The symbol of the spirit fire on earth was wilfully destroyed by the ignorant.
Tacitus  describes how much the Druids themselves conformed to the faith and surrendered to the will of the priests. He even mentions a leader of the Druid organization, namely Divicacius. This led to the defence against the Roman incursions being based not on blood and battle, but wickedly by means of magic. Huge oak forests were then burned for fear of the "demons" that inhabited them and, of course, lest any Druid could hide in them.
The Druids are often spoken of as mere soothsayers and fantasists, but the contrary was asserted by the Roman Caesar. The latter, although they were his enemies, had great respect for the ancient Celtic Druids and writes (in De Bello Gallico ) that the disciples of the Druids practiced a rigorous training that sometimes lasted up to twenty years, since nothing was written down. Everything was memorized in the form of poetic triads. The disciple received this training in caves and deep in the forests. The Druids were ancient Germanic, and schooled initiates. In England they continued to exist until the time of Queen Elizabeth in the 16th century.
Everything we can read in the Edda about the world of the ancient Germanic sagas goes back to the wisdom of the Druids. Indeed, the poet of the Edda was a Druid priest. The Druid priest spoke high truths, and though these were simple, they penetrated deeply into the human soul. These narratives built something into the human system so that in a subsequent incarnation these higher truths were understood because they were primed for it in a previous incarnation.
Much of what can be read in the Edda is about life and death and is based on actual events that were factual at the time of the ancient Druids. The Edda was the supreme and holiest saga at the time, but it became increasingly corrupted over time.
So the Druids primarily had spiritual leadership over the people they also ruled. They were regarded as the prescribed intermediaries between God and man; no one would perform a religious ceremony without the assistance of a Druid.
In public and private affairs, people submitted to the decision of the Druid. It was a great punishment for them when they were banned and denied participation in the religious ceremonies.
Caesar informs us:
Those who were exiled for refusing to submit to the decision of the Druids are counted among the lowliest and wicked. Everyone flees their company and avoids all conversation for fear of being contaminated by that close touch .
Caesar further writes of the Druids that they wanted their hearers to believe the following:
Souls are immortal: they pass from one form to another; they see this as the strongest stimulation, for they do not fear death. They also have much knowledge about the stars and their movements, about the size of the earth, about philosophy, and about the powers of the immortal gods, which they discuss with their young disciples.
Caesar seemed to be really interested in the Celts, but his interest had a special reason. Despite his respect for the Druids, he had a political concern. He knew that the Celts were dependent on their Druid priests, and he knew that if he wanted to destroy the Celts, he should start with the Druids: after all, they held the key positions!
In the northern part of Celtic Europe the educated initiates were also called 'cerunnes' (= deer). Here we can see a connection to the deity Cernunnos pointing to a deer cult. The ancient Celts worshiped even more animals: the dog, the deer, and the bull, all of which can be found on Gundestrup's cauldron .
The Gundestrup Cauldron
The decorations on the cauldron depict Celtic deities and rituals, which is why it is thought to have been used in Druid religious ceremonies.
On the Gundestrup cauldron, which probably dates from the La Tène period in the 2nd or 1st century BC, we can see a man in a meditative, sitting position with the antlers of a deer sprouting from the head. We can view this as a certain stage of development of spiritual connection with the cosmos. The connection with sun and moon can also be observed on this cauldron, which again indicates the fact that the Celts felt related to the ancient solar cult that goes back to the Hyperborean culture.
(To be continued in part 5)
 Pliny the Elder, The Natural History, chap 5
 Tacitus, Annals XIV
 J. Caesar, Gallic War , Book VI (chapters 11‑20)
 Jakob Streit, Sonne und Kreuz [Sun and Cross], Freies Geistesleben, Stuttgart 1977
 T.W. Rolleston, Myths and legends of the Celtic race, (first published 1911) Dover Publications, 1990
 F.C.J.Los, De Oud-Ierse kerk, Ondergange en opstanding van het Keltendom [The Old Irish Church, Fall and Resurrection of Celts], Vrij Geestesleven, Zeist 1975