The Concept of ‘Just War’ (Edexcel A-Level History): Revision Notes
The Concept of 'Just War'
The theological problem facing Pope Urban II
When Pope Urban II called for the First Crusade in 1095, he faced a serious religious challenge. He was asking 11th-century knights to travel to the Holy Land and kill Muslims in order to recapture Jerusalem, where Christ had been crucified and resurrected. However, this request posed a fundamental problem: it required knights to break one of the Ten Commandments – specifically, 'You shall not kill'.
The Ten Commandments were sacred religious laws that God had revealed to Moses, as recorded in the Bible. For medieval knights, who were deeply religious, the prospect of breaking one of these divine laws was extremely troubling. They believed that violating God's commandments would result in eternal damnation in hell.
This created a major obstacle for Urban's crusading plans – why would knights willingly risk their immortal souls?
Urban needed to find a way to convince these warriors that it would be acceptable, even righteous, to kill in this particular context. To solve this theological dilemma, he turned to Countess Mathilda of Tuscany for assistance in developing religious arguments that could be used in his sermons promoting the crusade.
Augustine of Hippo and the origins of just war theory
Countess Mathilda helped Pope Urban II by gathering a group of canonists (experts in church law) to develop and apply the concept of penitential warfare to the First Crusade. The most important of these canonists was Anselm II of Lucca.
The theoretical foundation for their work came from Augustine of Hippo, a highly influential early Christian theologian who had lived around 400 AD. Augustine had developed what became known as the just war theory. This theory argued that killing in warfare could be morally acceptable under certain specific conditions.
Augustine's Three Criteria for a Just War
According to Augustine, a war could be considered 'just' if it met three essential criteria:
- A good reason – there must be a legitimate and morally sound justification for the war
- Good intentions – those fighting must be motivated by pure and righteous purposes, not by greed, hatred or personal gain
- An official leader – the war must be authorised by a legitimate authority, not undertaken by individuals acting on their own
Key terms
Canonist: A person who studies church law and is an expert in it.
Penitential warfare: A war fought as a penance, or punishment, to make up for sins committed. A crusade is an early example of this type of war.
Applying just war theory to the First Crusade
The canonists working with Countess Mathilda adapted Augustine's theory to provide religious justification for the First Crusade. They argued that the crusade met all three conditions for a just war:
How the First Crusade Met Augustine's Just War Criteria
A good reason: The Holy Land was Christ's inheritance to the Christian Church. Jerusalem and the surrounding territory had also been part of the Roman Empire in earlier centuries. Therefore, Christians had a legitimate right to reclaim what rightfully belonged to them. The land was being held by Muslims, and recovering it for Christendom was presented as a justified cause.
Good intentions: The crusaders would be acting like pilgrims undertaking a holy journey. Their motivation would be love for Christ, not personal gain or worldly ambition. They were travelling to the place of Christ's crucifixion and resurrection out of devotion, making their intentions pure and spiritual.
An official leader: The First Crusade had been proclaimed by Pope Urban II himself. The pope was considered to be God's representative on Earth, the highest spiritual authority in the Christian world. His proclamation gave the crusade official sanction from the ultimate legitimate leader.
The development and purpose of just war arguments
These theological arguments were designed to persuade knights that they could participate in the crusade without endangering their souls. The theory provided a religious justification that allowed them to break the commandment 'You shall not kill' in this specific circumstance, because the killing would be done for righteous purposes under legitimate authority.
The Ongoing Development of Just War Arguments
The development of these ideas did not end with the First Crusade. Monks and scholars continued to create compilations of religious arguments that popes and preachers could use to convince later generations of crusaders. One particularly important example was the work of Gratian, a 12th-century canon lawyer who wrote the Concordia discordantium canonum (Harmony of Discordant Canons). This text provided a question-and-answer guide to just war theory, making it easier for preachers to address the concerns and doubts of potential crusaders.
From 1140 to 1190, these ideas were further developed and refined. Despite various elaborations and modifications, all of these theological works shared a common goal: they aimed to reassure people that participating in a crusade would not result in the damnation of their souls. Instead, crusading was presented as a legitimate and even praiseworthy religious act that could help atone for sins rather than add to them.
Key Points to Remember:
- Pope Urban II faced the challenge of convincing knights to kill Muslims for the crusade, which meant breaking the commandment 'You shall not kill'
- The just war theory, originally developed by Augustine of Hippo around 400 AD, provided a solution by arguing that killing could be acceptable under three conditions: good reason, good intentions and official leadership
- The theory was adapted to the First Crusade by arguing that Christians had the right to reclaim the Holy Land, crusaders were motivated by love of Christ like pilgrims, and the pope's authority made it legitimate
- Canon lawyers like Gratian created guides (such as the Concordia discordantium canonum) to help preachers convince crusaders throughout the 12th century
- The ultimate purpose of just war theory was to reassure crusaders that they could fight without damning their souls – in fact, crusading could serve as penitential warfare to atone for sins