Question: The Gospels frequently speak critically of the scribes and the Pharisees. I have an understanding of who the Pharisees were, but who were the scribes?
— Name, location withheld
Answer: The Scribes in Jesus’s time were those who devoted themselves to the study and interpretation of the Mosaic and biblical Law. They would write commentaries on it and were considered experts in its teachings and application to varying situations. Since they could write, they were often hired to produce written documents as needed, especially in the interpretation of the Law.
The scribes were also involved in preserving Scripture and would copy and recopy the sacred writings meticulously. It is largely through their work that the Old Testament is so well preserved. The scribes’ original aim was in earnest — to know and preserve the Law and encourage others to keep it.
But the scribes, even more than the Pharisees, were among those, as a group, who came into conflict with Jesus, often charging Jesus or his followers with violations of the Law. Jesus, for his part, said that the Scribes often went beyond interpretation of Scripture, adding many man-made traditions to what God had said. He argued that they were good at spelling out the letter of the Law but ignored its spirit, even making their additions more important than the Law itself (ie. Mk 7:13).
This led to many confrontations between Jesus and the scribes. A large portion of Jesus’ Sermon on the Mount (Mt 5-7) contrasted what the people had been taught by the scribes and what God actually wanted. He also denounced them, as a group, for their hypocrisy (ie. Mt 23). They knew the Law, and they taught it to others, but they did not obey it. Eventually, the scribes played a large part in having Jesus arrested and crucified (cf. Mt 26:57; Mk 15:1; Lk 22:2).
Hence, the scribes and Pharisees were distinct groups, though with some overlap, since presumably some scribes were Pharisees. Like the scribes, the Pharisees were also devoted legal experts — hence the partial overlap of membership of the two groups. But most of the Pharisees were not scribes in the professional sense, and they often depended on the work of scribes to come to their own conclusions about the Law.