The 4 principals
Person hood- Being uniquely created by God and having dignity. ex. We have our own dignity so that lets us rule over the animals.
Common Good- The respect for people, peace and security. ex. Seeing a starving man and giving him something to eat.
Solidarity- It is social charity and working together. ex. When you're in a community you watch out for each other.
Subsidiarity- Those that are affected by a decision should be the ones that make it. ex. When you are looking for a job you should be the one that makes the choice to take it or not.
A saint that showed social justice is Saint John of God. He then repented after how he didn't think he respected the common good so he tried to turn his life around. He eventually freed Christian captives so that they can be free and spread the word of God.
How to do this in Northeast Kansas
One way to show social justice is for Personhood: go visit the people in jail so when they get out they will want to turn over a new leaf.
Another way for common good is to build more homeless shelters so people have somewhere to live.
For subsidiarity the people can pick who they will marry and not let anyone choose for them.