Jainism
In Jainism, the understanding and implementation of ahimsa is more radical, scrupulous, and comprehensive than in any other religion. Non-violence is seen as the most essential religious duty for everyone (ahiṃsā paramo dharmaḥ, a statement often inscribed on Jain temples). Like in Hinduism, the aim is to prevent the accumulation of harmful karma. When Mahavira revived and reorganized the Jain movement in the 6th or 5th century BCE, ahimsa was already an established, strictly observed rule. Parshva, the earliest Jain Tirthankara, whom modern Western historians consider to be a historical figure, lived in about the 8th century BCE. He founded the community to which Mahavira’s parents belonged. Ahimsa was already part of the "Fourfold Restraint" (Caujjama), the vows taken by Parshva’s followers. In the times of Mahavira and in the following centuries, Jains were at odds with both Buddhists and followers of the Vedic religion or Hindus, whom they accused of negligence and inconsistency in the implementation of ahimsa. There is some evidence, however, that ancient Jain ascetics accepted meat as alms if the animal had not been specifically killed for them. Modern Jains deny this vehemently, especially with regard to Mahavira himself. According to the Jain tradition either lacto vegetarianism or veganism is mandatory.
The Jain concept of ahimsa is characterized by several aspects. It does not make any exception for ritual sacrificers and professional warrior-hunters. Killing of animals for food is absolutely ruled out. Jains also make considerable efforts not to injure plants in everyday life as far as possible. Though they admit that plants must be destroyed for the sake of food, they accept such violence only inasmuch as it is indispensable for human survival, and there are special instructions for preventing unnecessary violence against plants. Jains go out of their way so as not to hurt even small insects and other minuscule animals. For example, Jains often do not go out at night, when they are more likely to step upon an insect. In their view, injury caused by carelessness is like injury caused by deliberate action. Eating honey is strictly outlawed, as it would amount to violence against the bees. Some Jains abstain from farming because it inevitably entails unintentional killing or injuring of many small animals, such as worms and insects, but agriculture is not forbidden in general and there are Jain farmers. Additionally, because they consider harsh words to be a form of violence, they often keep a cloth to ritually cover their mouth, as a reminder not to allow violence in their speech.
In contrast, Jains agree with Hindus that violence in self-defense can be justified, and they agree that a soldier who kills enemies in combat is performing a legitimate duty. Jain communities accepted the use of military power for their defense, and there were Jain monarchs, military commanders, and soldiers.
Though, theoretically, all life forms are said to deserve full protection from all kinds of injury, Jains admit that this ideal cannot be completely implemented in practice. Hence, they recognize a hierarchy of life. Mobile beings are given higher protection than immobile ones. For the mobile beings, they distinguish between one-sensed, two-sensed, three-sensed, four-sensed and five-sensed ones; a one-sensed animal has touch as its only sensory modality. The more senses a being has, the more they care about its protection. Among the five-sensed beings, the rational ones (humans) are most strongly protected by Jain ahimsa. In the practice of ahimsa, the requirements are less strict for the lay persons who have undertaken anuvrata (Lesser Vows) than for the monastics who are bound by the Mahavrata "Great Vows".
Read more about this topic: Ahimsa