The Pharisees are important for two reasons. First, the Gospels portray them as one of the principal opposition groups to Jesus. Second, Judaism as we know it generally traces its roots back to the Pharisees. How so? The Mishnah, the first great document of Judaism in its normative form, ca. 200 C.E., includes teachings attributed to authorities known to us from other sources to be Pharisees. These are, in particular, Gamaliel and his son, Simeon. The Mishnah, moreover, regards Gamaliel's father, the great rabbi Hillel, as one of the chief authorities for the Mishnah's own traditions. It follows that, long after the period at hand, the Mishnah preserved teachings allegedly belonging to the Pharisees in the time of Jesus.
Describing the Pharisees is not easy. The reason is that when people describe that rather small group, they pass their opinion also on large issues of our own day. Jews tend to praise the Pharisees as the source of wisdom and learning, because, as I said, Jews also claim to trace their religious traditions to the Pharisees. Christians today violently attack Pharisees. Protestants emphasize the legalism of the Pharisees, another way of attacking what they conceive to be the legalism of the Roman Catholic communion. Catholics simply draw upon well-known judgments in the Gospels themselves, which portray the Pharisees as hypocrites. But often many Protestants and Catholics, speaking of the Pharisees of long ago, really mean (“perfidious”) Judaism of today. Consequently, it is unusually difficult to take up the Pharisees with that attitude of reasoned curiosity that makes learning a source of light. The best we can do is describe the sources of such information as we have about the group at hand.