Why would someone delay their own enlightenment to help others?

In Buddhism, a bodhisattva is someone who has reached, or is working toward, enlightenment, and the word often means someone who delays their own nirvana to help others reach Buddhahood. The reason is compassion: in Mahayana Buddhism, a bodhisattva wants to become a Buddha for the benefit of all beings, not only for themself. Some texts put it as a vow: "I shall not enter into final nirvana before all beings have been liberated."

Not every tradition sees it the same way. In Theravada Buddhism, a bodhisattva is an exceptional and rare individual, such as Maitreya. Mahayana Buddhism sees the path as open to everyone: anyone who generates bodhicitta, a spontaneous wish to attain Buddhahood for the sake of every sentient being, is a bodhisattva. Even the "delay" is debated. Some Mahayana texts say a bodhisattva must postpone awakening, while later texts describe a "non-abiding" nirvana that lets a Buddha keep acting in the world, so nothing needs postponing.

The oldest known story of becoming a bodhisattva is a vivid one. In a past life, the future Gautama Buddha met an earlier Buddha, Dipankara, offered him five blue lotuses and spread out his hair, or his whole body, for Dipankara to walk on, resolving to become a Buddha himself. Dipankara confirmed that he would. Early Buddhist authors read this as showing that a bodhisattva needs both a resolution made before a living Buddha and that Buddha's confirmation. One early school counted the road ahead at three "incalculable aeons" plus ninety-one more.

Bodhisattvas also became figures of devotion. Manjushri and Avalokiteshvara, who personify wisdom and compassion, are the two most important bodhisattvas in Mahayana. Tibetan Buddhists consider the Dalai Lamas emanations of Chenrezig, the bodhisattva of compassion, and kings of Sri Lanka were described as bodhisattvas as early as the third century.