look out for the leaven!

Today's Gospel has Jesus warning the disciples about the "yeast of the Pharisees" and the "yeast of Herod." Poor disciples! I'd probably jump to the same conclusion they did: "He's saying this because we're out of bread." You know, the natural thing is to interpret anything we hear in terms of what is on our mind. I think that is what makes it very, very hard these days to have a civil discourse about certain moral issues, but that is another issue. I just wonder what Jesus really meant here, in Mark's story. Is the "yeast of the Pharisees" different from the "yeast of Herod," or were they basically the same thing? Because it seems as though both the Pharisees and Herod needed to know the score; they needed to be able to control the outcome. In other words, they tried to keep the mystery out of life.