If a religious teaching is to be effective, it must be suited to the abilities and faculties of those to whom it is preached. If it is too profound for its listeners, they may be frightened by it and thus doubt their own abilities, or they may leave the assembly at which it is being preached. Even the earliest sūtras contain the idea that the Buddha adapted his teachings to fit the capabilities of his audience. The Buddha was often compared to a doctor who administered medicine to the sick. If the medicine (or doctrine) was not suited to their needs, it would not cure them. The Lotus Sūtra and the Hua yen Ching (Avatamsakasūtra) both contain passages which describe Śrāvakas and pratyekabuddhas who did not have faculties sufficiently mature to understand the Buddha’s more advanced teachings. These passages played key roles in Chih-i’s systems of classification of Buddhist teachings. The Hua yen Ching was criticized because it made no allowances for the faculties of its listeners. It was thus considered an ineffective teaching for most people, leaving them as if they were ‘deaf and dumb.’ The Lotus Sūtra, in contrast, did consider the faculties of its audience. According to the Lotus Sūtra, the Buddha waited until his listeners were ready to hear his ultimate teaching before preaching the Lotus Sūtra. Despite this, five-thousand people left the assembly at which the Buddha preached the Lotus Sūtra because of their “overweening pride.” On the basis of this passage, Chih-i was able to argue that the Nieh p’an Ching (Mahāparinirvāpasātra), traditionally regarded in China as the Buddha’s last sermon, had the function of saving these five-thousand monks and nuns. Chih-i thus classified the Nieh p’an Ching in the same period of the Buddha’s life as the Lotus Sūtra and noted that the Nieh p’an Ching included elements if the Perfect Teaching.