The Four Siddhāntas that are conveyed in the light of the Four Noble Truths in the Tripiṭaka, Common, and Separate Teachings, are relative teachings. The ultimate teaching of the Four Siddhāntas refers to the Perfect Teaching. Chih-i’s explanation of the Four Siddhāntas in terms of relative and ultimate that are related to each of the Four Teachings is as follows:

1. The Buddha employs only the first three Siddhāntas (i.e., Worldly Siddhānta, Siddhānta for Each Person, and Siddhānta of
   Counteraction) to expound the Four Noble Truths that belong to the Tripiṭaka Teaching. Since this teaching concerns analysis and disintegration of dharmas (entities) in perceiving emptiness and is to prepare listeners with lower faculties to be able to eventually receive Mahāyāna Teaching, it is unskillful in terms of the way of perceiving emptiness, and is relative.
2. The Four Siddhāntas the Buddha employs to expound the Four Noble Truths that belong to the Common Teaching are skillful, for the teaching concerns embodying dharmas in perceiving emptiness. That is, dharmas are empty therein. However, truth is dichotomized into the Absolute Truth and the Worldly Truth: the former concerns emptiness, and the latter empirical existence. This teaching of duality is relative.
3. The Four Siddhāntas the Buddha employs to expound the Four Noble Truths that belong to the Separate Teaching are profound, for this doctrine concerns the Middle Way of transcending the truths of emptiness and existence. However, this Middle Way does not identify emptiness with existence, and is still relative.
4. The Four Siddhāntas the Buddha employs to expound the Four Noble Truths that belong to the Perfect Teaching are ultimate and subtle. This is because this doctrine concerns the Middle Way that identifies emptiness with existence. For Chih-i, such a way of perceiving reality as an integrated unity of both emptiness and provisional existence is perfect and is the ultimate teaching of the Buddha. (Vol. 2, Page 43-44)

This is to explain that the formation of each of the Four Siddhāntas is different. The Worldly Siddhānta is formed in order to comply with what is enjoyed and desired (Sui-lo-yü) by people. The Siddhānta for Each Person is formed in order to comply with what is suitable to individuals (Sui-p’ien-i) and arouse their virtues. The Siddhānta of Counteraction is formed in order to deal with particular cases of individual sickness. The Siddhānta of the Supreme Truth is formed in order to transmit the Supreme Truth. According to Chih-i, each Siddhānta contains the Four Siddhāntas. In addition, the first Siddhānta (i.e., Worldly Siddhānta) embodies the beginning stage for living beings to strive for Buddhahood as the cause, and the last Siddhānta (i.e., Siddhānta of the Supreme Truth) embodies the final stage of attaining Buddhahood as the effect. (Vol. 2, Page 38)

The ten characteristics of each of the Four Siddhāntas

1. The Worldly Siddhānta is characterized as (i) speaking about phenomenon and noumenon to comply with conditions that are suitable to, and are pleasurable to be heard by audiences; (ii) explaining both the Provisional (Unreal) and the Real; (iii) combinations of causes and conditions that result in differences between good and evil beings; (iv) a separate view of the five aggregates (i.e., form, sensation, conception, volitional activity, and consciousness) that are taken as real; (v) differentiating wholesomeness from evil; (vi) viewing the three periods (past, present, and future) of time separately; (vii) separating the Four Wholesome Factors (Ssu-shan-ken) that belong to the Ordinary Ranks of a Higher Level (Nei-fan) from the Ordinary Ranks of a Lower Level (Wai-fan); (viii) to differentiate between “the Path of Vision” and “the Path of Cultivation (ix) neither “learning” nor “no-learning 47 and (x) the Siddhānta for Each Person that is contained within.
2. The Siddhānta for Each Person is characterized as (i) to arouse the wholesome mind that existed previously; (ii) to only talk about the Provisional (Unreal) of living beings; (iii) if wholesome conditions are combined, a wholesome person comes into being; (iv) from the wholesome five aggregates, the wholesome five aggregates can be reproduced; (v) to explain that the present wholesomeness can reproduce the future wholesomeness; (vi) concerning future period of time; (vii) concerning stages of “heat” and “summit”; (viii) concerning “the path of vision;” (ix) realizing the “learning and (x) the Siddhānta of Counteraction that is contained within.
3. The Siddhānta of Counteraction is characterized as (i) to get rid of new evil; (ii) to only talk about the Real (i.e., evil is real because it causes the real effect of generating more evil); (iii) when evil conditions are combined, an evil person comes into being; (iv) to destroy the evil five aggregates with the wholesome five aggregates; (v) to destroy the present evil with the present wholesomeness; (vi) concerning the present period oftime; (vii) concerning the Four Types of Mindfulness (Ch., Ssu-nien-ch’u; Skt., catvāri smṛtyupasthānāni) that are practiced together and individually$ l (viii) concerning “the path of cultivation”; (ix) cultivating the “learning”; and (x) the Siddhānta of the Supreme Truth that is contained within.
4. The Siddhānta of the Supreme Truth is characterized as (i) enabling a person to realize the path of a sage; (ii) not Unreal and not Real; (iii) not good and not evil; (iv) attaining the five aggregates with “non-defilement (v) neither good nor evil; (vi) attaining the negation of the three periods of time; (vii) attaining the Highest Mundane Dharma that is closest to “real non-defilement (viii) attaining “the path of no-learning”; (ix) attaining the arhatship of “no-learning”; and (x) the Supreme Truth that does not include the three other siddhāntas. (Vol. 2, Page 35-36)

The correspondence between the Four Siddhāntas and the Five Sections are: The Worldly Siddhānta corresponds with the Name; the Siddhānta of the Supreme Truth with the Substance; the Siddhānta for Each Person with the Gist; the Siddhānta of Counteraction with the Function; and to distinguish these Siddhānta is to correspond with the Characteristics of the Teachings. (Vol. 2, Page 33)

The description of the Worldly Siddhānta (Shih-chieh Hsi-t’an) is that the world is like a vehicle that comes into existence because of the combination of wheels, spokes, axle and rim. Human beings are likewise created because of the combination of five aggregates. The Buddha proclaims the worldly dharma of the correct causality to comply with living beings, with what they desire and with what they are pleased to hear, so that they can obtain the proper view of the world.

With regard to the Siddhānta for Each Person (Ko-ko Wei-jen Hsit’an), because of different capacities of people, certain doctrines the Buddha expounds are designed specifically for certain beings according to their degree of understanding.

The description of the Siddhānta of Counteraction (Tui-chih Hsit’an) is that for counteracting particular vices of living beings the Buddha offers different treatments.

The description of the Siddhānta of the Supreme Truth (Ti-i-i-ti Hsit’an) is that by knowing that his disciples are ready to receive the true teaching, the Buddha expounds the supreme truth in terms of “unexplainable” (Pu-k’o-shuo) and “explainable” (K’o-shuo). The true dharma, namely the truth of neither origination nor extinction (that transcends language, and is attained by the Buddha) is unexplainable. Although truth itself is unexplainable, i.e., it cannot be conceptualized and is beyond words, it is indeed necessary to be revealed for an educational and soteriological purpose. In this sense, Chih-i talks about truth that is explainable. The method of realizing the truth is provided by the formula of the Four Alternatives (Ch., S,su-chü; Skt., catusko/i), i.e., everything is real (I-ch ‘ieh-shih), everything is unreal (I-ch ‘ieh Pu-shih), everything is both real and unreal (I-ch ‘ieh I-shih I-pu-shih), and everything is neither real nor unreal (I-ch ‘ien Fei-shih Fei-pu-shih). (Vol. 2, Page 34)

With regard to the truth itself, the common view held by Buddhists is that it is indescribable and inexpressible and can only be reached by intuitive insight through contemplation. What is the point then for the Buddha to teach truth? Chih-i argues that the Buddha’s teaching is necessary for the sake of liberating sentient beings. Truth has to be delivered when there is need for it, namely, living beings have a need to hear the teachings in order to eliminate suffering and attain liberation.

The folding of mind is to take mind as the foundation. For Chih-i,
contemplating mind is to regard “the mind as the foundation for all dharmas” (Hsin-shih Chu-fa Chih-pen). This is because it is the mind in activity that generates karman (deeds), from which suffering arises. It is also the mind that embraces all dharmas or entities. In Chih-i’s system, the Ten Suchnesses and the Ten Dharma-realms represent all entities. Since the Ten Dharma-realms are the representation of the whole universe and they are embraced by the mind, mind can be taken as the universe. (Vol. 2, Page 31)

The unfolding of mind is to take mind as the substance, the gist, and the function. In Chih-i’s view, there are three types of mind: (i) the mind of affliction (Fan-nao Hsin) which includes three links: ignorance (Ch., Wu-ming; Skt., avidyā), desire (Ch., Ai; Skt., tṛṣṇā), and attachment (Ch., Ch’ü; Skt., upādāna), (ii) the mind of suffering as effect (K’u-kuo Hsin) which includes seven links: consciousness (Ch., Shih; Skt., vijn͂āna), name-and-form (Ch., Ming-se; Skt., nāmarūpa), the six senses (Ch., Liu-ju; Skt., ṣaḍāyatana), contact (Ch., Ch’u; Skt., sparśa), sensation (Ch., Shou; Skt., vedanā), rebirth (Ch., Sheng; Skt.,jāti), and old age-and-death (Ch., Lao-ssu; Skt.,jarāmarava), and (iii) the mind of karman (Yeh Hsin) which includes two links: volitional activity (Ch., Hsing; Skt., saṃskāra), and existence (Ch., Yu; Skt., bhava). When these three types of mind are identified with the Dharma-body, perfect wisdom, and liberation, they are taken as the Substance, the Gist, and the Function. Chih-i says that if the mind of suffering is identical to the dharmakāya (Dharma-body), the mind is taken as the Substance (Hsin-t’i). If the mind of affliction is identical to prajn͂ā (perfect wisdom), the mind is taken as the Gist (Hsin-tsung). If the mind of karman is identical to liberation, the mind is taken as the Function (Hsin-yung). The “Characteristics of the Teaching” that concerns mind is the overview of both “unfolding” and “folding”. When mind differentiates (i.e., the aspect of unfolding) with regard to the Twelvefold Causality (Ch., Shih-erh Yin-yüan; Skt., dvādaśāṅgaprat̄tyasamupāda), six worlds (hell-dwellers, hungry ghosts, animals, asuras, humans, and heavenly beings) arise. This is because the mind differentiation is a result of one’s ignorance that generates the twelve links of dependent origination, and keeps one in the cycle of the six worlds. Only if the mind is put to rest and no longer differentiates (i.e., the aspect of folding), can one depart from ignorance. Subsequently, the four levels of sages (i.e., śrāvakas, pratyekabuddhas, bodhisattvas, and Buddhas) arise. (Vol. 2, Page 31)

This is the third analogy for the Five Sections, indicating the completeness of the Five Sections in elaborating the teaching of the Buddha as a whole. The human body (Jen-shen) is analogous with the section “Name”, for the name indicates the general characteristics of the teaching of the Buddha. The other four sections indicate the specific characteristics of the teaching of the Buddha. Chih-i says that “Substance” is analogous with consciousness (Shih); “Gist” is analogous with life (Ming), “Function” is analogous with heat (Nuan), and “Characteristics of the Teaching” is analogous with the mind that distinguishes (Fen-pieh).

These five types of polarity are Chih-i’s summarization of various aspects of the teaching of the Buddha.

1. The polar concept “phenomenon and noumenon” can summarize the doctrinal aspect of Buddhism, for the doctrines expounded by the Buddha center on phenomenon as the Worldly Truth and noumenon as the Absolute Truth.
2. The polar concept, “teaching and practice”, can summarize the major components that constitute Buddhism, for Buddhism is about the teaching of the Buddha and one’s practice of attaining liberation according to the teaching.
3. The polar concept, “cause and effect”, can summarize the nature of Buddhism}for Buddhism concerns nothing else but the practice for attaining enlightenment as the cause and the attainment of enlightenment as the effect.
4. The polar concept, “self-cultivation and transforming others”, can summarize the functional aspect of Buddhism, for self-cultivation is the knowledge of penetrating the truth, and transforming others is the knowledge of benefiting others.
5. The polar concept, “speech and silence”, can summarize the methods of the Buddha’s teaching, for both speech and silence are for t!le purpose of teaching and transforming others.

Since these five types of polarity reveal different aspects of Buddhism, together, they represent Buddhism as a whole, and therefore, are related more or less to each of the Five Sections. (Vol. 2, Page 27)