Based on such evidence it is difficult to conjure up an accurate image of them. There are three main firsthand witnesses to consider. Josephus calls the Sadducees one of the main Jewish "philosophies", by which he means an intellectual school. But Josephus is clearly less than happy with them in comparison to the other main Jewish philosophies, the Pharisees and Essenes.
The Sadducees reject the immortality of the soul, emphasize free will over fate, and generally dissent from traditions and customs. He identifies them as aristocratic in their interests and contrarian in their disposition—in contrast to the more popular Pharisees and idealistic Essenes.
Many historians associate the Sadducees with the priests of the Jewish Temple because Josephus says that they supported the high priest’s family against King Herod. Then historians go one step further and maintain that the Sadducees collaborated with the Roman overlords.
The second witness comes from the Bible. The New Testament offers a slightly different, but better known, picture: The Sadducees can scarcely be differentiated from the Pharisees, and thus Christians often assume that they collaborated with the Pharisees.
In the popular mind the Sadducees and Pharisees form a common front against Jesus (Christ) of Nazareth. The New Testament says that the Sadducees do not believe in a resurrection of the dead, an afterlife reward or punishment, and an invisible spirit-filled universe.
They are located in Jerusalem and active in the Temple, perhaps as priests, and members of the centralized ruling council called the Sanhedrin. Because Romans would have insisted on dealing with ethnic authorities, the likely assumption is that the Sadducees were collaborators.
The rabbis, as the third witness, distinguish the Sadducees as opponents to the Pharisees. They make the Sadducees the foils for their own "correct" positions, since they conjure up for themselves a Pharisaical background.
Specifically, the rabbis would have readers believe that Pharisees and Sadducees disagree on purity issues, the role of civil rulers, temple ritual, and Sabbath observance customs, all of which are of vital concern to rabbinic Judaism. Like Josephus and the New Testament, the Talmud says that they do not believe in the resurrection of the dead.
The Sadducees’ teachings were conservative. Fathers of the church such as Origen believed that the Sadducees rejected divine inspiration outside of the Torah (the first five books of the Bible), but this is something of an exaggeration.
Nonetheless, the sources agree that the Sadducees were suspicious of later Jewish ideas of a final judgment, heaven and hell, and heavenly beings—and these ideas are not found in the early books of the Bible. They are temple-based and so would most likely be suspicious of efforts to spiritualize or decentralize the religion.
They possibly were more pro-Roman because they wanted to keep the temple cult operating and protect their privileged position. Most likely they were among the most active in the conspiracy against Jesus.
Since some Pharisees are identified as priests, and some priests cannot be identified as Sadducees, Sadducees should not simply be exclusively seen as part of the priestly clan, nor can all high priests be seen as Sadducees.