The topic of War is one that draws the attention of philosophers to a vast array of sub-topics and nuances that need to be explored in order to understand the subject. It is a topic that can lead to endless philosophical discussion and, in many cases, the exploration of a single argument could take the form of an entire book.

The underlying concept of war can be regarded as the use of violence by states to assert control over territory or resources. It is a central idea within modern political philosophy and it has been the focus of much debate.

A number of philosophers have argued that war is an intrinsic aspect of the universe and as such, there is little that can be done to prevent it from occurring. These theories have a common thread in the fact that they rely on a Heraclitean or Hegelian perspective of the world in which change, whether it is physical, social or political occurs through violence and war.

Other philosophical perspectives attempting to understand the nature of war are often concerned with what causes it and how it can be prevented. This can be approached from a variety of angles, from a view of man as an essentially violent animal to a desire for global peace and co-operation. Theories of the causes of war generally fall into two broad categories; those describing innate biological and psychological drives and those relating to social relations and institutions. Both camps contain optimists and pessimists concerning the preventability of war.

Some philosophers explore the role that religion plays in the causes of war. Others believe that the causes are more mundane such as security failures, which can trigger disproportionate retaliation that escalates in a vicious circle (as in the assassination of Archduke Franz Ferdinand and Sophie Duchess of Hohenberg in Sarajevo, 1914, which triggered World War I). Some, like Hobbes, have an atomistic conception of mankind in which individuals are pitted against each other and prompted to seek a contract between themselves for peace. Others, invoking John Donne’s notion that no man is an island and Aristotle’s view that man is a political animal, argue that man’s ability to either negotiate for peace or to wage war depends upon the society in which he lives.

The cultural, social and ideological roots of bellicosity also deserve a great deal of study. The conflation of long-term anthropological and psychological characteristics with more specific societal and cultural circumstances leads to a wide range of explanations for the origin of war that must be examined in their entirety.