In terms of “explaining retinues that are formed by karmic connection” (Ming Yeh-sheng Chüan-shu), what Chih-i assert is that, although all living beings are the children of the Buddha, some, after taking poison, have lost their minds, and some have not. The ones, who did not lose their mind, seek for help and take the given medicine. Chih-i argues that the Lotus Sūtra is analogous with medicine, through which the family-tie between the Buddha and living beings, as a father and son relationship is formed. For the ones who have lost their mind, the Buddha applies expedient means to form a karmic connection with them by expounding different doctrines of the Fourfold Teaching. When a karmic connection is formed, with the twenty-five kinds of samādhi, the Buddha expounds the Threefold Truth to sentient beings in the twenty-five kinds of existence, so that they can be matured. Chih-i emphasizes that, regardless of whether some of them may have been liberated and may not have yet, they are all retinues of the Buddha. (Vol. 2, Page 291)

In terms of “explaining retinues that are formed by individual vows” (Ming Yüan-sheng Chüan-shu), this category of retinues is referred by Chih-i to the beings that had affinity with the Buddha in their previous lives, and because of their vows, they are reborn in this lifetime to attend the Buddha. If they attained the Path in this lifetime, they are referred by Chih-i as internal retinues (Nei Chüan-shu), and if they have not attained the Path, they are referred by Chih-i as external retinues (Wai Chüan-shu). These external retinues have to wait for the future Buddha to come in order to attain enlightenment. (Vol. 2, Page 291)

In terms of “explaining retinues that are formed by principal nature” (Ming Li-hsing Chüan-shu), what Chih-i attempts to convey is that every being possesses the Buddha-nature. The relationship is thus formed by this inherent nature for attaining Buddhahood. Chih-i argues that the fundamental principle of the Buddha-nature that is equally possessed by sentient beings and the Buddha is evidenced in the Buddha’s statement in the Lotus Sūtra, emphasizing that all living beings are his children. Therefore, retinues that are formed by principal nature indicate children and father relationship between sentient beings and the Buddha. (Vol. 2, Page 290-291)

In terms of “explaining retinues that are formed by principal nature” (Ming Li-hsing Chüan-shu), what Chih-i attempts to convey is that every being possesses the Buddha-nature. The relationship is thus formed by this inherent nature for attaining Buddhahood. Chih-i argues that the fundamental principle of the Buddha-nature that is equally possessed by sentient beings and the Buddha is evidenced in the Buddha’s statement in the Lotus Sūtra, emphasizing that all living beings are his children. Therefore, retinues that are formed by principal nature indicate children and father relationship between sentient beings and the Buddha. (Vol. 2, Page 290-291)

For the meaning of retinues, Chih-i explains that retinues refer to the Buddhist practitioners, who, after receiving the precepts or the method of meditation, carry out practices in accordance with the teaching, and are able to conceive an aspiration to attain precept, concentration and wisdom. Because of their practice that accords with the dharma, the dharma becomes a teacher, and the practitioner a disciple. A family tie is developed in due cause. Chih-i asserts:

“[The Buddha] teaches various Dharma-doors that enter the mind of beings. Because of the dharma, intimacy is formed; because of intimacy, [one] has faith in [the teaching of the Buddha]; because of the faith, one becomes subservient to [the teaching of the Buddha]. This is called Retinues.” (Vol. 2, Page 290)

[In Chih-i’s view,] the Lotus Sūtra as the perfect teaching is justified as it contains the subtlety of the twelve types of scripture. The following is Chih-i’s explanation of why the twelve types of scripture contained in the Lotus Sūtra are considered to be subtle.

1. llsiu-to-luo (Sūtra) as the prose portion is called the direct speech, and contains the subtlety of the Lotus Sūtra, for this prose form of sūtra directly expounds the Middle Way as the knowledge of the Buddha.
2. Chih-yeh (Geya) as the verse form is subtle, for it is the repetition of the prose portion that sūtra represents, and concerns the doctrine of the Middle way.
3. Chia-t ‘o (Gāthā) as the independent verse is subtle. This is because, the verse portion in the Lotus Sūtra regarding the dragon girl who attained Buddhahood in one instant is independent, i.e., it is not the reiteration of the prose portion. This portion in verse form describes the dragon daughter who attains enlightenment in one second, which proves that the independent verse portion gāthā is subtle.
4. Pen-shih (Itivṛttaka) that concerns the past lives of the disciples of the Buddha is subtle, whereas twenty thousand Buddhas do not teach anything else but the unsurpassed Path.
5. Pen-sheng (Jātaka) that concerns the previous lives of the Buddha is subtle, for it is the story about the material body of the Buddha being born as a prince, and the dharmakāya being manifested as a bodhisattva.
6. Yin-yüan (Nidāna) as the historical narratives is subtle, for the Buddha repeatedly proclaims the Greater Vehicle to beings, regardless of whether they are of the Lesser Vehicle, or of the Human and Heavenly Vehicle.
7. Wei-ts ‘eng-yu (Adbhutadharma) that concerns rare events is subtle, for the auspicious signs the Buddha manifests, such as heavenly flowers raining down, the trembling of the earth, the ray of light exerting from between the Buddha’s eyebrows, and transforming land three times, are inconceivable.
8. P’i-yü (Avadāna) that concerns allegories is subtle, for the title of the Lotus Sūtra uses the word Fa (dharma) as a metaphor for nothing else but the disclosure of the Three Vehicles (śrāvaka, pratyekabuddha and bodhisattva) and the revelation of the One Buddha-vehicle.
9. Lun-i (Upadeśa) that concerns the discussions of doctrine is subtle. This is evidenced by the interaction between the dragon girl and the bodhisattva Wisdom Accumulation. The bodhisattva Wisdom Accumulation, being attached to the Separate Teaching and being suspicious of the Perfect Teaching, did not believe that the dragon girl can instantly attain Buddhahood. The dragon girl, after declaring that the Buddha can testify and see the possibility of her attainment of Buddhahood in one second, offered the Buddha a precious gem. Chih-i explains that the gem represents perfection, which is to answer the disciple of the Separate Teaching by means of the Perfect Teaching.
10. Wu-wen Tzu-shuo (Udāna) that concerns the self-generated statement of the Buddha is subtle, for it is mentioned in the Lotus Sūtra that the Buddha speaks by himself without being questioned in order to praise the Buddha-wisdom.
11. Shou-chi (Vyākaraṇa) that concerns prophecies of the Buddha is subtle, for it is mentioned in the Lotus Sūtra that the Buddha prophesizes listeners’ future Buddhahood. They will be able to peacefully abide in the ultimate wisdom and be revered by humans and heavenly beings.
12. Fang-kuang (Vaipulya) that means correct and universal is indicated by the Buddha-vehicle and the Buddha-wisdom the Lotus Sūtra upholds, for the Buddha-vehicle is superior and universal, and the Buddha-wisdom is profound and abstruse.

The above is the description of the Subtlety of Expounding the Dharma. This subtlety represents the teaching of the Buddha in terms of the twelve types of scripture. In Chih-i’s view, all divisions of Buddhism whether of Śrāvakayāna or Mahāyāna are the “Word of the Buddha.” It is due to different circumstances and different capacities of beings that the teaching of the Buddha varies in order to suit specific situations. Since the Buddha’s proclamation of the dharma is spoken of in terms of the twelve types of scripture, the twelve types of scripture incorporate all teachings of the Buddha.

Yet, how do the twelve types of scripture fit into Chih-i’s system of classification in terms of the Four Teachings (Tripiṭaka, Common, Separate and Perfect), in which the Perfect Teaching is exclusively subtle? First, it must be determined whether the teaching (Neng-ch’üan) and the doctrine (Suo-ch’üan) of each of the Four Teachings are coarse or subtle. The Tripiṭaka Teaching is coarse in terms of both the teaching and doctrine; the Common Teaching is coarse in terms of doctrine, and subtle in terms of teaching; the Separate Teaching is coarse in terms of teaching, and subtle in terms of doctrine; and the Perfect Teaching is subtle in terms of both teaching and doctrine. Therefore, the Perfect Teaching is subtle only. Second, various sūtras must be examined, that are expounded in the five periods of the Buddha’s teaching, from which the Lotus Sūtra is said to contain one Perfect Teaching only. Third, since the Lotus Sūtra represents the Perfect Teaching, the former is perfect. Such a perfect feature is reflected by the subtlety of the twenty types of scripture that are contained in the Lotus Sūtra. (Page 287-289)

Chih-i points out that although various sūtras entail the same subtle teaching like that of the Lotus Sūtra, they also contain coarse explanations, which cannot be integrated with the subtlety. Therefore, these sūtras are coarse. The uniqueness of the Lotus Sūtra is revealed in two perspectives. First, it entails only one perfect explanation, i.e., reality is an integrated unity, since it is upright without any expedient means, and only presents the unsurpassed Path of Buddhahood. Second, the coarseness is integrated with the subtlety, and therefore, the coarseness is subtle as well. (Vol. 2, Page 287)

Different types of the Buddha’s teaching are associated with the capabilities of living beings. Yüan refers to the conditions with regard to living beings. This is to say that the different teachings of the Buddha are the outcome of the Buddha addressing various capabilities of sentient beings. Chih-i delineates:

“Yüan refers to the dharma of causes and conditions in the Ten Dharmarealms that form living beings. All these living beings possess the root and the nature of the Ten Dharma-realms.”

Therefore, in order to deal with different situations, the Buddha has to teach them in a manner suitable to their conditions. The mature ones get the response from the Buddha earlier. The Buddha knows whether or not beings are mature, and he responds to them accordingly. Of those who are not mature, the Buddha does not abandon them completely. Instead, he limits his teachings to the human and heavenly vehicle (Chihtsuo Jen-tien-sh’eng Shuo), which does not belong to any of the twelve divisions of scripture. To the mature ones, such as the one with the faculties of the Lesser Vehicle, the Buddha’s teaching can be classified into twelve, or nine, or eleven types. To the beings that have the potentiality of becoming bodhisattva, the Buddha bestows the teaching in twelve divisions. In general, Chih-i emphasizes that the dharma in twelve divisions is the result of the Tathāgata’s teaching as corresponding to four kinds of situations, leading to the formation of the Fourfold Teaching. (Vol. 2, Page 284)

What is involved in saving beings is not only the metamorphoses of the Buddha’s own body in identifying with the body and mind of sentient beings, but also the transformation of his own land in identifying with the lands where beings live. Chih-i announces that the supra-mundane powers the Buddha applies are either coarse or subtle in the other three teachings (Tripiṭaka, Common and Separate) except for the ones in the Perfect Teaching in the Lotus Sūtra that are subtle only. The expedient powers the Buddha applies for the beings in the nine Dharma-realms are coarse, except for the ones that are for the beings in the Buddha Dharma-realm; whether pure or filthy, wide or narrow, all the latter powers are subtle, since they are the real and true spiritual powers.

The above is the description of the Subtlety of Supra-mundane Powers. The Buddha’s use of supra-mundane powers is the second step in teaching and transforming others. This is because the Buddha’s teaching is so profound that only supra-mundane powers can shock and awaken beings and can be the means of preparing audiences and enabling them to hear and accept the teaching. (Vol. 2, Page 278)

By presenting the three wheels of the Buddha that represent the Buddha’s teaching and transformation of beings, Chih-i argues that the Buddha’s teaching is not separate from the use of supra-mundane power: the Buddha uses supra-mundane power first before he begins to expound the dharma. Using supra-mundane power is associated with the body-wheel, and expounding the dharma is associated with the verbal turning of the wheel and the wheel of knowing the mind of others. (Vol. 2, Page 276)