Chapter 34 of Genesis recounts the story know as the Rape of Dina.  The prince of Shechem (himself also named Shechem) captures and rapes Dina, the daughter of Leah and Jacob. Hamor, Shechem’s father and the king comes to ask Jacob to let his son marry Dina. Shimon and Levi conceive a plan to consent and then kill all the inhabitants of Shechem. They justify their plan, which they do implement, because they cannot let their sister be treated this way with impunity. The city’s population has passively permitted their prince to violate Dina and therefore they are also guilty.

Once the decision is taken, it is it actually makes sense to kill all the inhabitants however cruel that is. It is wise because were they to leave a remnant, that remnant would one day organize and take revenge. By killing everyone, Shimon and Levi ensure that their clan can live in peace. Jacob, however, is still afraid that the people of Shechem had military pacts with their neighbors and the neighbors would come and attack him and his family. This does not happen because although there may have been some military agreements, once Shechem is entirely wiped out, there is no incentive for any other tribe to attack Jacob. They stand to gain nothing and only risk losing the battle. A pact is only useful as long as both parties exist!

So perhaps Shimon and Levi’s attack on Shechem was justified. But it had other consequences which were very damaging to Jacob’s family.

Years later in the story of the family the brothers come down to Egypt to buy grain. Joseph decides to lock up Shimon as a guarantee that the brothers will return with Benjamin. Rashi explains why Joseph chose to lock up Shimon. Shimon was the brother who threw Joseph into the pit. See Rashi on 42:24.  Even if the violence of Shimon and Levi was legitimate, it had a bad affect on them. Shimon and Levi learned that violence solves problems, and it solves them maybe too well. They then used violence against their own family, against Joseph, to solve what they perceived as a problem. Their former actions corrupted them.

Golda Meir famously said,

“When peace comes, we will perhaps in time be able to forgive the Arabs for killing our sons, but it will be harder for us to forgive them for having forced us to kill their sons. “(London 1969)

Killing corrupts the killer and teaches him that violence works. He may come use violence to solve his problems also in his civilian life and in his family life. This is a danger and a problem society faces after every war. A soldier needs to go through a detoxification process where he learns to make a mental separation between his behavior in war and his behavior back home.

Unfortunately this did not take place in time for Shimon and Levi. What did eventually happen was the harnessing of this violent tendency for good in the case of Levi. When the people built and worshiped the golden calf in the times of Moses, it was Levi that came in at God’s behest to killed the trespassers.  Perhaps Joseph locked up Shimon with this in mind, that his time in the Egyptian jail would serve as his detox.