The Just War theory

• Belief in the sanctity of life underlies the Christian version of the Just War theory
• In its very early history, the Church was largely pacifist
• Over the centuries, the Just War theory was developed, largely by Augustine and Aquinas
• Who were the main people involved in the development of the Just War theory?


  Augustine and Aquinas
• There are two main parts to the theory:

  • lus ad bellum: which addresses the conditions when going to war might be justifiable
  • lus in bello: which addresses the way in which a war must be fought
• lus ad bellum:

  refers to criteria for deciding when going to war might be justifiable
• lus in bello:

  refers to criteria for deciding how war, once started, must be fought
• ius ad bellum:

  • just cause
  • legitimate authority
  • right intention
  • probability of success
  • proportionality
• ius in bello:

  • discrimination (between civilians and fighters)
  • proportionality or means to ends