The large amount of manuscript fragments found at Qumran and in the other places of the Dead Sea is what remains of a religious library. There are only rare examples of texts that could be classified as scientific. For example, the so-called astronomical works found in the fourth cave (called 4Q Brontologion), or a list of trees in the writings of Enoch found in the fourth cave, or even the explanation for the circulation of blood in one copy of 4QD (the famous Damascus Document).
The Qumran’s Library belonged to a religious sect that lived in a community that had settled in the marl terrace that stretched above the steep cliffs where the eleven caves were found. The community was a sect, i.e. a separate group from the official Judaism of the time. The Jews living in this settlement followed a cultic calendar different from the official one in force in Jerusalem. They lived isolated from the surrounding world, avoiding contacts with people outside the community.
Many of the texts found in the caves were written by Jews who lived at Qumran, while many others are simply copies of the texts with different origins. The so called sectarian texts include the pesharim, i.e. Bible commentaries. Norman Golb thinks that the texts found at Qumran have no relationship with the Jews living in the community. The texts came from different libraries in Jerusalem and therefore they reflect the flourishing literary activity of that time. This theory is now widely rejected, because no one doubts that the texts found in caves are – although in different ways – in connection with the sect that lived in Qumran.
In the manuscripts the people who wrote the texts was called in different ways: community (in Hebr. yachad), assembly (in Hebr. edah) the children of Sadok, the children of light, members of the new covenant, etc. It may be that they were members of the Essenes, one of three sects alongside Pharisees and Sadducees. In fact, the presentation of the Essenes made by Flavius Josephus coincides with the lifestyle of the group of Jews who had settled at Qumran. However it would be wrong to identify the Essenes with the Qumran community. In general the Essenes did not live segregated from the rest of the world and their communities were scattered throughout the Judea. To understand the identity of the group at Qumran we have to understand why it broke with the Judaism.
The Qumran’s people separated from Jerusalem because the religious leaders prescribed a different religious calendar with a different organization of the festivals. The schism also occurred because of the different way of interpreting the laws contained in the Bible, concerning the Temple, the cult and ritual purity issues of people and objects. The Qumran texts speak of a mysterious Teacher of Righteousness opposed to a Wicked Priest. The Teacher of Righteousness stated that God revealed him how to correctly comment the biblical texts. So he left Jerusalem with other people.
There is much discussion about the identity of the Wicked Priest. For some it would be Jonathan Maccabeus (King of Judah from 161 to 143 BC) who was appointed high priest by the Syrian king Alessandro Balas although not belonging to the official priestly class, namely the priestly class of Sadok. So the Teacher of Righteousness could be the legitimate high priest who left Jerusalem and fled with a group of followers, at Qumran. According Florentino Garcia Martinez the Teacher of Righteousness represents the whole succession of wicked priests, i.e. the high priests that didn’t belong to the official class of sadocites, from Jonathan Maccabee until Alexander Jannaeus. According to this hypothesis, the Essenes would be separated from Jerusalem under the high priesthood of John Hyrcanus, who was also Hasmonean king of Judah from 134 to 104 BC