The Hrdaya Sutra, or Heart Sutra, is the topic under consideration. According to Grand Master Chih I (538-597 C.E.) of the Tíien Tíai Sect, any speaker who endeavors to explain one of the Mahayana sutras should cover five points of the scriptureís profound meaning, or five profundities. What are they? They are as follows:

1) Explanation of terms and names 
2) Definition of the substance. 
3) Clarification of the principles. 
4) Discussion of its (the sutraís) application. 
5) Discernment of the doctrine.

The five profundities regarding this Sutra are as follows: The Dharma and the example stand for the name. All dharmas are empty (or void) of substance. Nothing there to be attained is the principle. Elimination of the three hindrances (greed, hatred and ignorance) is the application, and the ripening of the fruit is the doctrine. All of what follows will provide further explanation.

In order to explain its name, the Sutra should be seen and distinguished within the context of all of the Buddhaís teaching. Altogether, there were seven reasons for naming a sutra according to seven categories, as follows: The first category consists simply of the name of the speaker of a particular sutraófor example, Amitabha Sutra, Vimalakirti Sutra, etc. In the second category, the name designates the teaching conveyed by that particular discourse, such as Nirvana Sutra or Mahaprajna Paramita Sutra, to give two examples. In the third category, the sutras are named to elucidate the doctrine they teach by analogy. The title Brahmajala Sutra derives from the net of banners used for the adornment of the palace of Mahabrahma. Each eye of the net is said to have contained a mani-jewel, and its brightness reflected all the others ad infinitum. Likewise, the Buddhadharma is forever reflected through the brightness of the radiant minds of all Bodhisattvas. In the fourth category, the sutras are named after the person(s) seeking Dharma from the Buddhaóe.g., the Sutra of Prajna for the Benevolent King spoken by the Buddha. In that sutra, the Buddha teaches sixteen benevolent kings. The Buddha and the kings are the persons, and Prajna is the Dharma. The fifth category combines an example specific to each case and the Dharma. The namePrajna Paramita Hrdaya (Heart) Sutra, for example, consists of Prajna Paramita, which is the Dharma, and Hrdaya, or Heart, which is the specific example. More will be said on this subject later.

In the sixth category, the name of a sutra expresses a connection between a person or a being and an object or event that is the clue to the Dharma. The title The Sutra of the Bodhisattvaís Necklace, to give an example, hints at the transcendental adornments of a highly accomplished spiritual being. The Bodhisattva is the being, the necklace is the object, and their connection is the clue to the Dharma.

The combination of the teacherís name and the name of the Dharma with an analogue are included in the seventh category of titles. Consider, for instance, the title Buddhavatamsaka Mahavaipulya Sutra: The Buddha is the teacher, Mahavaipulya is the Dharma, and Avatamsaka is the analogue. The Buddha attained the fruit of Buddhahood because he returned all the causes of all actions. Avatamsaka is the analogue, the ground of Buddhahood. Maha means great, suggesting that, in this instance, the doctrine is applied universally and accommodates all the other doctrines. Vaipulya stands for function of pure karma in all places. Because of Buddhaís attainment of that stage, the mind encompasses the universe, and everything in the ten directions is the Buddha-sphere. Furthermore, each of the Buddha-spheres encompasses a chiliocosm. This is over the heads of most people because their only knowledge of this world is based on their narrow outlooks. To repeat then, the above seven categories of titles as relevant to Mahayana sutras are based on either of the following: individual(s); a particular Dharma; an analogue; or any combination of these.

The title of The Prajna Paramita Heart (or Hrdaya) Sutra combines Dharma, i.e., the Prajna Paramita, with a specific exampleóHeart or Hrdaya. The terms used are in Sanskrit: Prajna means wisdom, and Prajna Paramita stands for wisdom acquired experientially, by means of intuitive insight, and perfected, through cultivation, to the level of transcendental knowledge; it is just the Original Wisdom of the mind, or the True Mind. Why, then, add words to it? Because that Sutra is axiomatic for the entire collection of the Prajna Paramita scriptures. Just as we consider the heart to be the center of the body, that Sutra is the center and distills the essence of all the Prajna Paramita texts.

Originally, since time immemorial, Prajna has manifested itself as intuitive wisdom in all sentient beings. That is known as former wisdom, or wisdom of life. However, people became confused through grasping, and the True Mind, fogged over by perverted views, manifested itself as obsessive thought-patterns. The cycle of birth-and-death never stops turning the Wheel of Life-and-Death, and it is difficult to get off. Actually, however, the True Mind is never separate from us, not even for one moment.

The Buddha spoke the Prajna Paramita Dharma for close to twenty-two years. Recorded and compiled, the resulting text consisted of six hundred scrolls, and it was delivered in sixteen meetings of the Assembly. The differences that existed were merely differences in expedient means adjusted to suit a particular potential; and, in every case, the aim was to free those who listened from perverted views, help them to abandon grasping, and teach them to return to the original source and understand their True Mind. In other words, the Prajna teaching is aimed at removing confusion, bringing about the recognition of oneís own True Mind, and returning to the truth. According to this doctrine, the mind has three layers: the first is the layer of the deluded mind; the second is the Prajna Mind; and the third is the center, the heart, or the pivot of the Prajna mind, which also is the relation of this Sutra to the doctrine. The Heart Sutra is the axis of all the Prajna Paramita teachings. Taking further the example of the mind, one might call The Heart Sutra the absolute center of the central sutras. If we compare the core of this Sutra with the mind of worldly people, the mind of Prajna is the true mind; and the mind of worldlings is the deluded mind.

Again, the absolute center of the mindís center may be perceived as consisting of three layers: the mind of worldlings, the mind of Saints and Bodhisattvas, and the mind of Buddhas. Minds of worldlings are immersed in suffering of many kinds. In contrast, the mind of a saint, the first level, represents the accomplished individual of the Two Vehicles, or a Bodhisattva; and at the center of mindís center is the Buddha, the Ultimate or True Mind. The mind of the Prajna Paramita Sutra is the True Mind, also referred to as the Essential Wisdom. The Essential Wisdom we are speaking of is to be distinguished from the awareness of objects or the environment and their use and value, which usually characterized as knowledge by worldly people.

The term Paramita is Sanskrit, and it means reaching the other shore. The Prajna Paramita, or the Wonderful Wisdom, courses like a boat, transporting all sentient beings across the sea of defilement to the other shore that is Nirvana. The word Nirvana, also Sanskrit, means transcending birth and death or, simply, liberation. The Prajna Paramita is, therefore, the Essential Wisdom and the center of all kinds of prajna. Almost every sutra functions on two levels simultaneously: One level is general; the other is specific. However, the Prajna Paramita Heart Sutra is just specific; although its title includes the word sutra due to usage, the text does not function at the general level.

Sutra in Sanskrit originally meant to uphold; and when applied to principles, it upholds the principles of all the Buddhas whether moving upward, downward, or upholding sentient beings according to their potential. If the one who understands Buddhadharma upholds the principles of all the past Buddhas, he or she can liberate sentient beings. Whoever can understand the theory behind the flawless, accomplished Buddha, can also understand how to uphold the potential of sentient beings. Sutra, then, means a shortcut and a well frequented path. Finally, it means the way to Complete Enlightenment.

The second profundity is the definition of substance. What, then, is the substance of The Heart Sutra? Starting with ìSariputra, the characteristics of the voidness of all dharmas are non-arisingî through ìthere is no wisdom, and there is no attainment whatsoeverî is the definition of its substance. Consequently, ìthe characteristics of the voidness of all dharmasî is the substance of this Sutra.

The third profundity is focused on the clarification of the purpose of a sutra. Since we already understand the meaning of this Sutraís name as well as the meaning of its substance, we should have no difficulty understanding its principle or purpose. We should understand its principle according to the sentence ìThere is nothing to be attained.î When there is nothing to attain, one is able to discern the characteristics of Emptiness.

As to the discussion of the application of this Sutraóit being the fourth profundityóit is to break off the three obstacles. What are these? They are as follows: passions; deeds (past karma); and retribution. Problems, worries and suffering all are related directly to the three obstacles.

There are two kinds of retribution: being the resultant person; being in the dependent condition(s). Being the resultant person means being what we are physically, our bodies. Some are strong and in good health, so others respect them for it. Some are unsightly and unwholesome, so others dislike them. The strong, the weak, the long-lived and the short-lived, the beautiful and the ugly, the wise as well as the foolish, all have varied causes in their previous lives and, accordingly, receive diverse effects in their present existence. Those who have produced good causes in their previous existences enjoy good health, longevity, beauty and wisdom in this life. In contrast, those who generated evil causes in their past lives have various deficiencies and shortcomings in the present. This, then, is what being a resultant person means.

Being in the dependent condition(s) relates to oneís circumstances, including clothing, sustenance and shelter. Obviously, those who have all their needs satisfied live happily; favorable events occur, yet they do not now have to exert themselves because of good causes in their previous lives. A resultant person relies on the dependent conditions for survival, and the conditions, in turn, have their causes in his or her past existences. However, good karmaópractice and deeds that benefit others in the presentówill produce favorable effects in oneís future existences.

The connection between cause and effect must not be doubted. The obstacles resulting from past deeds come into existence because we live in this world. It really does not make any difference who is a lay person and who is a monk or a nun. Most are involved in interactions inevitably connected with existence within society, which frequently produce circumstances generating obstacles through karma. There are three kinds of karma: good, bad and transcendental.

The obstacle of passion arises as retribution for deeds done in the past. The circumstances produced, then, are favorable or adverse according to karma. Striving to achieve oneís goal combines with the confusion that usually accompanies it, producing numerous defilements, and the result is suffering. That is the obstacle of passion. The original defilements are six in number: greed, hatred, ignorance, the aggregates, doubt, and heterodox views.

All three obstacles are severed naturally when the meaning this Sutra is thoroughly understood since the application of this Sutra is the breaking off of the three obstacles. To get rid of the three obstructions is to be released from many kinds of suffering. Suffering is all-pervasive, and even devas must endure it, though to a much lesser degree than human beings. Therefore, the purpose of all Buddhadharma is to depart from suffering and to dwell in happiness.

Discernment of the doctrine is the fifth profundity. Since we have already reached some understanding as to the meaning of the Sutra in terms of the four profunditiesói.e., its name, substance, principles and applicationówe are now in a position to proceed to a discussion of this last one: The entire body of the Buddhaís teaching can be divided into five phases; and using the example of the five ways in which milk is used to provide nourishment can be applied to situate The Heart Sutra in its proper position in the entire context of the Buddhaís teachings.

While teaching, the Buddha frequently referred to the example of the white cow of Snow Mountain. On the slopes of Snow Mountain grow many varieties of grass that make cows healthy and strong. The milk is wholesome and rich in nutrients and helps those who drink it to survive better. Similarly, the Buddhadharma can nourish our wisdom, and, thus, the example of the five uses of milk appropriately illustrates the five stages of the Buddhaís teaching.

Initially, the Buddha delivered the essence of the Avatamsaka Sutra (Hwa Yen in Chinese), it being the first phase of his teaching. It was the teaching as formulated in the Mahayana sutras, and those people with obstructions could not rise to its level. It was like offering fresh raw milk to a baby; those with obstructions could not digest its message.

The second phase is represented by the Agamas, which are comparable to thin, sour milk. The Buddha spoke the Avatamsaka Sutra first so that the eyes of Mahayana Bodhisattvas would open to the view and awareness of the Buddhas. At that time, many with shallow roots could not and would not accept these highest teachings. Though they had eyes, they could not see; though they had ears, they could not hear; though they had mouths, they could not ask. It was as if they were blind, deaf and mute. The Buddha continued teaching the Avatamsaka for twenty-one days to convert all those with Bodhisattva potential. Many who could not listen formulated, later on, the Theravada tradition. In the Deer Park, the Buddha chose to teach the Agamas, thereby making his teaching comparatively easier to understand. Five of his friends attained deep understanding and became his first disciples, and that marked the beginning of what later became the Theravada tradition. The Buddha taught the Agamas for close to twelve years. Those who could not follow the teachings during the Avatamsaka phase can be compared to babies who, unable to digest fresh milk, can take it thinned down or after it is allowed to turn. The teaching of the Agamas is comparable to milk that is, thus, made easier to digest.

The third phase is the Vaipulya, interpreted as containing the doctrines of equal relevance. This phase is comparable to milk of full strength that is allowed to turn in order to be easily digestible. During that time the Buddha spoke four kinds of teachings, and the division into Theravada and Mahayana was not marked. This phase is said to have lasted for approximately eight years.

The fourth phase, that of Prajna, is believed to have lasted for twenty-two years; it can be compared to the ripened curd. The nourishment it provides is concentrated as well as being easily digestible.

The fifth phase relates to the Saddharma Pundarika Sutra and to the Nirvana Sutra. In contrast to the milk simile above, this phase has the quality of clarified butter. During that period the Buddha is said to have taught Mahayana Dharma, the unimpeded teaching pointing directly at the mind.

To summarize, the Buddha taught Dharma in five stages, and each of these displays two facts: expediency and reality. Expediency means following the causes and conditions (such as the sentiment and potential of sentient beings in a given situation); reality equals Truth or the absence of falsehood. The Buddha spoke the truth of his unsurpassed Wisdom directly. The five stages can profitably be reviewed for their expediency-reality balance:

1) The earliest stage, that of the Avatamsaka Mahavaipulya Sutra, is said to consist of expediency and reality (or truth) in equal proportion. Expediency means promoting the understanding of reality. The teaching of reality makes entry into the Wisdom of Buddhas possible. Thus, the first stage includes both expediency and reality.

2) The stage of the Agamas is focused on expediency. The Buddha adapted his teachings to the potential of sentient beings, specifically of those in the world; consequently, he did not discuss the superb Dharma at that time. Agama is a Sanskrit term, meaning incomparable. The term incomparable Dharma is intended to convey the conviction that nothing can be compared with the Agamas.

3) In the Vaipulya stage, the proportion between expediency and reality is about three parts to one, expediency being predominant. What are the expedient teachings? The first expedient teaching was later developed into the sutra section of the Tripitaka. It deals with the Two Vehiclesósravaka and pratyekabuddhaóin relation to their ending the cycle of birth-and-death in terms of allotment only, but not ending the cycle of mortal changes. Nevertheless, the Two Vehicles have birth and death. The second expedient teaching of the third stage is the earliest formulation of Mahayana, specifically, the Dharma of the attainment of non-birth. The third expedient is the teaching of differentiation. The fourth expedient teaching belonging to this stage is the Dharma of Reality. Manifesting progressively the doctrine of perfect teachings during the third stage, the Buddha is said to have taught these four different approaches.

4) The stage of Prajna, or the fourth stage, is reflected in the Prajna scriptures. It is said to be composed of two parts expediency and one part reality; i.e., it is the Mahayana teaching, or the Great Vehicle.

5) The fifth stage, that of the Saddharma Pundarika and Nirvana Sutras, is the stage of the Dharma of Reality, or Truth, without concern regarding expediency. At that stage, the Buddha had little time left and could not afford to spend it worrying about the potential of the Assembly. Following his delivery of The Sutra o f Bequeathed Teaching during his final period, the Buddha entered his final Nirvana.

The Heart Sutra, the topic of the detailed commentary below, belongs to the fourth stage according to the above scheme. It is said to consist of two parts expediency and one part reality, and it is comparable to well-ripened curd.