Contemporary terrorism has many and varied forms and causes. Terrorist ideologies can be classified under the general typologies of religious fanaticism, anarchism, neo-nazism and neo-fascism, separatism, nationalism, and issues orientation (e.g., abortion, environmental, and anti-nuclear causes). Within or in addition to such ideologies, there are ideological mercenaries, pathological terrorists, and counterterror terrorists. The use of violence against innocent persons to advance these ideologies or to intimidate people into changing their attitudes and behavior to comply with a terrorist ideology has been rationalized as a justified means of achieving an admirable and valued goal or state of affairs. Terrorists hope that by publicizing their cause even through heinous acts, people will come to appreciate the justice and value of their ideology; however, people whose lives are impacted by terrorist violence are not likely to become converts. No cause, however just or noble in the minds of the perpetrators of violence, can make such actions acceptable to their victims. The right of self- determination, for example, if it must be secured by the wrong of the murder and maiming of innocent persons, will not be viewed as worth the price in the eyes of the rest of the world. The chapter concludes with discussion questions regarding the ideology behind and justification for various notorious acts of violence. 8 suggested readings and 19 notes