25 And it came to pass on the third day, when they were sore, that two of the sons of Jacob, Simeon and Levi, Dinah’s brethren, took each man his sword, and came upon the city boldly, and slew all the males. 

26 And they slew Hamor and Shechem his son with the edge of the sword, and took Dinah out of Shechem’s house, and went out. 

28 They took their sheep, and their oxen, and their asses, and that which was in the city, and that which was in the field, 

29 And all their wealth, and all their little ones, and their wives took they captive, and spoiled even all that was in the house.

The men of the city had shown a complete lack of conscience in how they treated the rape of Dinah. Their blindness to their own offense ended up being their own undoing, though. For one who is blind to the fact that they have done anything wrong is also blind to the fact that their might be a vengeance brewing.

And so, in their haste to fulfill the requirement given by Jacob’s sons, all the men of the city were circumcised at the same time, meaning that all of them were compromised at the same time. There was no battalion of whole men kept as a reserve to protect them from sudden attacks. This was the moment of total weakness that Jacob’s sons had calculated for, and in their wrath Simeon and Levi descended upon the city and killed every male.

There is a powerful lesson here of what happens when an entire community collectively loses their conscience. Ecclesiastes 9:15 speaks of a city being saved by a single wise man. So long as their remains one who can see things as they truly are there remains hope. But what if there is no wise man? What if there is no one of conscience who can accurately predict consequences from actions? In that case the entire city is vulnerable. They will work their own destruction, and not even know they are doing so until it has consumed them.