War and Peace

HideShow resource information
  • Created by: kelsey
  • Created on: 05-12-13 16:49

Just War Theory

People were too easily starting wars. 

St augustine

  • The war has to be declared by legitimate authority 
  • There must be a just cause

St Thomas Aquinas

  • There must be just intention
1 of 16

Jus ad bellum and Jus in bello

Just ad bellum (before war) (the right to war in just war)

  • Must have just cause
  • declared by component authority (eg. the government)
  • must be a comparison of justice on both sides
  • must be a last resort
  • should be a reasonable likelihood of success
  • must have proportionality (good expected)

Jus in bello (during war) (reasons for war to be okay)

  • reasonable proportion between injustice being fought and suffering inflicted by war
  • proportionality must be excersised (actual fighting)
  • warfare must be discriminate
2 of 16

The problem of war

  • Presents major challenge to the morality of the modern world.
  • from a religious perspective, war is problematic
  • religous views are varied. The 'holy war' and the crusades is one example of religious war, however some are complete pacifists. 

Some distinctions of war 

  • Holy war: when god tells someone to go to war. Divine sanction. Losing the war will mean you have been unfaithful to god, and winning would mean god has stayed by your side. 
  • Just war theory: can be justified under certain conditions
  • Realism: the theory that wars can be a positive force for combating evil and advancing moral good
  • Pacifism: the theory that wars can never ever be morally justified. 'Non-violence'
3 of 16

Origins of the just war theory

Developed by St Augustine - a christian philosopher.

  • the earliest christians were pacifists, however when the romans converted to christian in the early 4th century, they needed do build an army to protect the roman empire. 
  • aquinas looked at the bible for justification and found a lot of different ideas within. he thought a clear case would be made for justified christian warfare.

Christianity and war

  • jesus seems to condemn all forms of violence in the new testement: "blessed are the peace makers" and he proved this when he did not fight against the people who tried to crucify him. 
  • in the old testement god commands a number of wars against israel's ememies. "the LORD is a warrior" god sometimes approves of war, particulalry protection against your people and foreign gods.

Looking at this, aquinas developed the just war theory. He divided it into two parts: jus ad bellum and jus in bello. Thomas aquinas developed these in the 13th century. He said that the intention should be to have less death or sin that what would happen if you had not fought. 

4 of 16

Thomas Aquinas

Just authority

  • Must be ordered by a component and legitimate authority (king, people)

Just cause 

  • there must be reason for going to war in the first place

Just intention 

  • the war must be intended to achieve some good outcome(eg. lasting peace)
5 of 16

Suarez and de vitora

Jus ad bellum was even more modified in the 16th century by francisco suarez and francisco de vitora.


  • The injustice which lead to the war must be proportionate to the damage it causes

Last resort:

  • All peaceful alternatives must first have been attemted

Reasonable chance of success:

  • A war can only be just if it can succeed. hopeless wars are immoral.
6 of 16

The catholic bishops

In 1983 they modified it even more in their statement 'the promise of peace' they said jus ad bellum shoukd include one extra criterion.

 Comparative justice:

  • The intrests of both sides should be taken into consideration

"Wars are rarely just because they are usually one sided. Governments seldom think of their enemies when waging war."

7 of 16

Applying jus ad bellum to WWII

For being a just war:  

  • Winston Churchill was a just authority, and britain was a parlimentary democracy.
  • In 1939 a german army made an unprovoked attack on poland. Poland was an ally of Britain so it gave them a just cause.
  • Allys wanted to remove Adolf Hitler from power, so they had a just intention.
  • Britain did everything they could to avoid war with germany. War was a last resort.
  • They had reasonable chance of success.
  • Because germany did not win the war, it has become a much better place, and has benefited civilians, so comparative justice was served.

Against being a just war:

  • The war started quite badly for the allies and they were desperate for success. they would do anything to get an advantage, including the bombing of large civilian areas such as Dresden. This makes it questionable as to weather they fought with proportionality.


8 of 16

Jus in bello

Just practices in war

Regulates the way in which christian nations fight each other.


  • Only killing or capturing active participants.


  • Only using measures which are fitting and humane.

Hague conventions:

  • Set of agreements designed to regulate military conduct, banning cruel weapons such as bullets which expand of flatten easily in the human body.

Geneva conventions:

  • Protect prisioners of war, outlawing torture and other cruel forms of treatment.
9 of 16

Strengths of just war theory

  • It fits with commonly accepted views of justice, allowing wars to defend, protect of prevent a humanitarian disaster. 
  • Realistic, as fair as possible.
  • Provides important checks on state's use of force. 
10 of 16

Weaknesses of Just war theory

  • Contradicts teachings of jesus, he brings message of peace in the gospels.
  • Aquinas contradicts himself: claims all life is sacred, yet allows killing and warfare. 
  • Actually encourages war, suggests war can be positive.
  • Criteria can be manipulated for evil purposes. Germany faked a series of 'polish attacks' to give them a just cause for invading.
11 of 16


  • Violence is wrong in any circumstance.
  • Just war theory is often seen as inadaquate.
  • Looking back historically many christians have been pacifists, For example jesus in the teaching of the gospels lived non-violently.
  • The very first christians refused to join the roman army.

Conciensious objective: Say no to going to war

12 of 16

Religious, Christian pacifism

"Do not resist and evil person, if someone strikes you on the right cheek, turn to him the other also." (Matthew 5)

"They that take the sword shall perish with the sword." (Matthew 26)

"We totally oppose all wars, all preparation for war, all use of weapons and coercion by force, and military alliances." (Quaker peace testimony)

13 of 16

Principle Pacifism

The deontoligical absolutist view:

  • Violence is always intrinsically wrong, people must always seek to preserve life
  • Can be supported with the sanctaty of life argument: if it is wrong to murder somone then it sould be wrong to go to war.
14 of 16

Other types of pacifism


  • Peaceful solutions should always be the first choice, but not an absolute objection to war.
  • Wars might sometimes be allowed.


  • Peaceful approaches to conflict because they work better.
  • Non violent campaigns like the bus boycott.
15 of 16

Critisisms of pacifism

  • We can reject underlying principles: life may not be instrinsically valuble
  • Utilitarians may say that it is sometimes alright to kill, it is the greater good.
  • It is unrealistic because wars will happen. 
  • Violence is sometimes necessary to defeat evil (WWII)
16 of 16


No comments have yet been made

Similar Religious Studies resources:

See all Religious Studies resources »See all Ethics resources »