Political terrorism – Violent criminal behaviour designed primarily to generate fear in the community, or substantial segment of it, for political purposes. Non-Political terrorism – Terrorism that is not aimed at political purposes but which exhibits "conscious design to create and maintain a high degree of fear for coercive purposes, but the end is individual or collective gain rather than the achievement of a political objective". Anonymous terrorism – In the two decades prior to 2016–19, "fewer than half" of all terrorist attacks were either "claimed by their perpetrators or convincingly attributed by governments to specific terrorist groups". A number of theories have been advanced as to why this has happened. Quasi-terrorism – The activities incidental to the commission of crimes of violence that are similar in form and method to genuine terrorism but which nevertheless lack its essential ingredient. It is not the main purpose of the quasi-terrorists to induce terror in the immediate victim as in the case of genuine terrorism, but the quasi-terrorist uses the modalities and techniques of the genuine terrorist and produces similar consequences and reaction. For example, the fleeing felon who takes hostages is a quasi-terrorist, whose methods are similar to those of the genuine terrorist but whose purposes are quite different. Limited political terrorism – Genuine political terrorism is characterized by a revolutionary approach; limited political terrorism refers to "acts of terrorism which are committed for ideological or political motives but which are not part of a concerted campaign to capture control of the state".
During the Reign of Terror, which began in July 1793 and lasted thirteen months, Paris was governed by the Committee of Public Safety who oversaw a regime of mass executions and public purges.Prior to the French Revolution, ancient philosophers wrote about tyrannicide, as tyranny was seen as the greatest political threat to Greco-Roman civilization. Medieval philosophers were similarly occupied with the concept of tyranny, though the analysis of some theologians like Thomas Aquinas drew a distinction between usurpers, who could be killed by anyone, and legitimate rulers who abused their power—the latter, in Aquinas view, could only be punished by a public authority. John of Salisbury was the first medieval Christian scholar to defend tyrannicide. Most scholars today trace the origins of the modern tactic of terrorism to the Jewish Sicarii Zealots who attacked Romans and Jews in 1st-century Palestine. They follow its development from the Persian Order of Assassins through to 19th-century anarchists. The "Reign of Terror" is usually regarded as an issue of etymology. The term terrorism has generally been used to describe violence by non-state actors rather than government violence since the 19th-century Anarchist Movement.In December 1795, Edmund Burke used the word "Terrorists" in a description of the new French government called Directory:
At length, after a terrible struggle, the [Directory] Troops prevailed over the Citizens ... To secure them further, they have a strong corps of irregulars, ready armed.