Combat: armed and unarmed conflict between individuals and groups

A fundamental distinction is made between martial and sporting combat, that is, between a violent and a playful or symbolic competition. In violent competition, the opponents face each other as enemies. Whether symbolic fighting means preparation for violence or renunciation of violence has been debated since ancient times. In the modern Western view, symbolic or sporting combat is also intended to create a sense of fairness that would be preserved in a serious contest. The line between sporting and serious confrontation blurs, for example, in economic competition or competition between rivals in relationship matters.

Playful fights can also be observed in the animal world. Anatomically modern humans (Homo sapiens) have created a wide variety of athletic competition to peacefully compete or entertain themselves within the framework of agreed upon rules. Competitions can bring recognition or prizes, sometimes scorn or pity. The risk of losing can increase motivation rather than decrease it.

When fighting becomes an ideological demand, a "right of the strongest" can result, for example in so-called Social Darwinism.

For as long as there have been living things evolved enough to intentionally harm others, there have been fights. Fights for resources, reproduction partners, territories, etc. are an essential part of evolution. However, among more highly evolved animals (e.g. primates), increasingly sophisticated methods of avoiding or peacefully settling aggression (cf. social behaviour) have also evolved, such as non-lethal fights for rank, gestures of submission, expressions of affection and the like.

Man, through his intelligence, has developed tactics for waging battles, acting in an organized manner and using an ever-increasing amount of effort to achieve an advantage. Increasingly sophisticated propaganda techniques were developed to motivate people to participate in disputes, utilizing ideologies and emotionalizations such as enemy images or religious justifications. Weapons technology became more and more sophisticated, as did psychological methods to demotivate the enemy.

Humans also developed more civilized solutions to (potential) conflicts, such as the use of courts, markets and other institutions, or politics and diplomacy. Large armies and arsenals are said to serve to prevent wars (e.g., by creating a power vacuum) rather than to conduct them. A strong police force may serve a comparable purpose. An escalation from initially civilized to violent strife is, and always has been, nevertheless possible.

The Christian world order of the European Middle Ages with its utopia of a renunciation of violence on the one hand and a certain tolerance for rule-breaking on the other (forgiveness of sins) has led to today's monopoly of violence by the state. It is supposed to prevent vigilante justice and to base every fight on rules of the game or a procedure. This development since the 13th/14th century was examined by the sociologist Norbert Elias in his major work On the Process of Civilization. He wondered how the duel of the medieval robber barons could become a clearly regulated aristocratic duel, when the nobility no longer lived scattered but were increasingly drawn together into large courts. From this, Elias tried to understand why traffic rules in the large cities of the 20th century functioned without leading to constant confrontations between the participants.

Since the 18th century (in Britain since the Glorious Revolution, in continental Europe essentially only after the French Revolution), modern sports gradually developed in the Western world, and in Japan, also since the 18th century, modern martial arts such as Kendō, peaceful forms of fighting.

The American Revolution of 1776 marked the beginning of the establishment of social systems that, above all, brought about a reconciliation of interests internally by democratic means. However, this revolution, as well as later revolutions in Europe, did not solve all social conflicts in the long term, which led to social movements, some of which were militant in orientation, and which still have the right today, in the form of modern institutionalised trade unions, to organise labour disputes, in particular, in order to enforce the interests of their members with their employers. As a rule, such struggles today are non-violent, but with work stoppages and lock-outs, the opponents of the struggle harm each other materially. In the USA and South Africa, social movements have even had to ensure equality for people of different skin colour. In their beginnings, these modern movements are often divided for a while into a part practicing non-violence or at most civil disobedience, and a part that is at least rhetorically ready for violence.

In the second half of the 19th century, the prevention of armed conflicts in and between most European states was partly achieved through the idea of an external threat (nationalism). At the same time, the willingness to use violence against minorities within and against other nations increased as a result of propaganda, social upheaval (industrialization), simplistic Darwinian beliefs, a perceived threat to the "old order" through demands for the elimination of grievances, and other factors. In particular, nationalist ideas led to World War I, social grievances to the October Revolution, and simplistic racist enemy images to World War II and the Holocaust.

The warlike history of mankind reached a previous climax in the Second World War, which probably claimed more than 50 million lives.