The most important idea in Jainism is that the entire world is animated: even stones, rocks and water have life. Non-injury to living beings, especially to humans, animals, plants and insects, is central to Jaina philosophy. In fact, the principle of ahimsa, emphasised within Jainism, has left its mark on Indian thinking as a whole. According to Jaina teachings, the cycle of birth and rebirth is shaped through karma. Asceticism and penance are required to free oneself from the cycle of karma. This can be achieved only by renouncing the world; therefore, monastic existence is a necessary condition of salvation.