St. Thomas Aquinas made important contributions to our understanding of justice, especially in politics. Here are the main points:

1. What is Justice?
   Aquinas says that justice is a good quality that helps people give each person what they deserve. He believed that justice is important for communities and helps keep society in order.

2. Natural Law:
   A big idea in Aquinas's thinking is natural law. This means that human-made laws should match up with the universal rules and moral values that are part of human nature. He believed that laws that are unfair aren't real laws and should be ignored. This idea sparked future thoughts on civil disobedience.

3. Different Types of Justice:
   Aquinas talked about four kinds of justice:

   • Commutative Justice: This is about being fair in exchanges between people.
   • Distributive Justice: This means sharing resources fairly from the community to its members.
   • Social Justice: This protects the common good and makes sure that everyone in society is taken care of.
   • Legal Justice: This is about what individuals owe to their government.

4. Justice and Virtue:
   Aquinas thought that justice works together with other important qualities, like wisdom, self-control, and bravery. He believed that a fair society needs good citizens, which gives political ideas a strong moral base.

5. Impact of His Ideas:
   Aquinas's ideas on justice greatly shaped medieval thought and continued to influence later periods, like the Renaissance and modern political theory. His work helped develop concepts of social contracts and human rights. Today, his ideas still play a role in discussions about right and wrong in politics.

In summary, St. Thomas Aquinas showed how justice is key to creating a well-organized society.