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Engaging Faith: Practical lesson ideas and activities for Catholic Educators

February 25, 2010

Catholic Just War Theory Lesson Plan

What is Just War Theory? Just War Theory, often called just-war tradition or just war doctrine, is “a set of principles developed through the centuries by the Catholic Church that clearly outlines when a nation may ethically participate in a war…and sets clear limits on armed force once a war is engaged (Pennock, Catholic Social Teaching, p. 185) an important teaching of the Catholic Church. Based on the writings of St. Augustine and St. Thomas Aquinas, the Church has set forth the following criteria for a “just war”:

Principles to follow in entering a war:

  • Just Cause – There must be real, lasting, grace and certain damage inflicted by an aggressor on a nation or community of nations.
  • Legitimate Authority – The right to declare a war belongs to the people who legitimately represent the people of a certain nation.
  • Comparative Justice – The rights and values involved in the conflict must be important enough to justify killing.
  • Right Intention – The war must be waged with a commitment to post-war reconciliation and peace, not personal gain.
  • Probability of Success – The odds of success should be compared to the likely cost of human life.
  • Proportionality – The damage and costs of the war should be proportionate to the good expected.
  • Last Resort – All peaceful efforts have been tried and exhausted before entering into war.

Standards to follow in fighting:

  • Immunity of Noncombatants – Civilians may not be the object of direct attack.
  • Proportionality – Only the minimum force necessary to obtain military objectives is used.
  • Right Intention – Leaders must keep in mind that only peace and justice is the aim of war.

Catholic Just War Lesson Plan


SWBAT develop a criteria for a just war.
SWBAT describe each criteria of a Just War.
SWBAT critique their own idea of a just war based on Catholic Just War Doctrine.
SWBAT apply just war theory to a modern conflict.
SWBAT take a position on a modern conflict as a just or unjust war.


  • Debate
  • Essay with supporting arguments

Lesson plan:

1) Creating a Class Criteria

Divide the class into groups of 4 and have them brainstorm criteria for a just war Have each group share their criteria and discuss as a class which criteria from each group will be use to create a master class-criteria.

2) Apply their criteria to a conflict they have studied in their social studies class. (e.g. based on what they know about the American Revolution, would the war be just based on their criteria?)

3) Provide the background to the Catholic just-war tradition

Develop a lecture based on the material above.

For some background (or to create handouts) see:

4) Discuss the differences between Catholic just-war tradition and the criteria that the class created previously. What did we have in common? Does the just-war tradition add something we missed?

5) Have the students apply the criteria for a just war to a modern conflict. Conflicts could include the war in Iraq and Afghanistan and possible conflicts with North Korean, Iran, or Sudan.

Have students research a specific conflict by giving them time in the computer lab or at home to develop a report.

Or, create a lecture/PowerPoint with specific information for the students to use in applying the just-war tradition.

6) Debate the conflicts – is it a just war?

Give students time to prepare their arguments based on the just war criteria. If there are no students on the opposing side, you should take them on in opposition.

To keep students occupied who are not in the debate, have them complete a graphic organizer that directs them to list and/or critique arguments of each side. Afterwards give them the opportunity to ask questions.

7) Conclude the lesson with an essay assignment in which students must apply just-war tradition to the conflict of their choice.

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