Pacifism isn't quite as old as war, but its roots go back to ancient times. Perhaps the first major pacifist figure was Siddhartha, the founder of Buddhism, who broke with the tradition of his warrior caste in India sometime between 400 and 600 B.C.E. and taught his followers that it was wrong to inflict suffering on any living thing [source: Walters and Jarrell]. One of the first great Buddhist Indian kings, Ashoka, renounced wars of conquest because of his beliefs [source: Britannica].
Followers of the Greek philosophy of Stoicism believed that individuals should resolve conflicts peacefully if not groups [source: Britannica]. In the first century C.E., Jesus preached the virtue of not resisting evil with violence, instead instructing his followers, "If anyone slaps you on the right cheek, turn to them the other cheek as well" (Matthew 5:39). In 296, one of his followers — a Roman named Maximilian — took that message to heart, and refused to serve in the Empire's legions, which led to his execution [source: Williams].
But pacifist ideas began to flower in earnest in late Renaissance Europe. In the early 1500s, the Dutch writer Erasmus argued that Christianity and war were irreconcilable, and "building a city is much better than destroying one" [Erasmus.org].
Pacifist religious denominations such as the Quakers and Mennonites looked for safe havens in colonial America, where some of them declined to participate in the Revolutionary War because of their beliefs [source: Yoder].
In the 1800s, the carnage of the Napoleonic Wars helped stimulate the rise of pacifist groups such as the London Peace Society, which promoted the idea that arguments between nations should be resolved without resorting to violence [source: Brown].
Many of the 19th century's most prominent intellectuals espoused pacifist beliefs, including Russian novelist Leo Tolstoy, whose Christian beliefs led him to reject the use of force by society to maintain order, and French economist Frédéric Passy, who organized an international peace conference in Paris in 1878 and was awarded the Nobel Prize for his peace activism [sources: McKeogh, Nobelprize.org].