“Expedient Means” chapter ［方便品］ ( Hōben-bon): The second chapter of the Lotus Sutra, in which Shakyamuni Buddha reveals that the purpose of a Buddha’s advent in the world is to lead all people to enlightenment. Shakyamuni shows that all people have the potential for Buddhahood, namely, that Buddhahood is not separate from ordinary people but is inherent in their lives. It is the principal chapter of the theoretical teaching (first half) of the Lotus Sutra and one of the two pivotal chapters of the entire sutra, the other being the “Life Span” (sixteenth) chapter, the core of the essential teaching (latter half). At the beginning of the second chapter, Shakyamuni arises from the deep meditation called the samādhi of the origin of immeasurable meanings, and addresses Shāriputra, declaring that the wisdom of the Buddhas is infinitely profound and immeasurable, far beyond the comprehension of voice-hearers and cause-awakened ones. Only Buddhas, he says, can realize the true aspect of all phenomena, which consists of appearance, nature, entity, power, influence, internal cause, relation, latent effect, manifest effect, and consistency from beginning to end. This revelation that all living beings of the Ten Worlds are innately endowed with and can manifest the true aspect identified as “the ten factors of life” establishes a theoretical basis for the subsequent assertion that all people have the potential to attain Buddhahood. Based on this passage, T’ien-t’ai (538–597) established the principle of three thousand realms in a single moment of life.
Shakyamuni then reveals that the Buddhas make their advent for “one great reason”: to enable all people to attain the same enlightenment as themselves. According to the chapter, their purpose is “to open the door of Buddha wisdom to all living beings, to show the Buddha wisdom to living beings, to cause living beings to awaken to the Buddha wisdom, and induce living beings to enter the path of Buddha wisdom.” Shakyamuni goes on to state that the three vehicles, or the teachings for voice-hearers, cause-awakened ones, and bodhisattvas, are not ends in themselves, but are expedient means by which he leads people to the one Buddha vehicle. This concept is referred to as “the replacement of the three vehicles with the one vehicle.”