Emptiness is form, and form is emptiness.
This forms the heart of the Heart Sutra. There are many interpretations. The standard in most Japanese dictionaries is simply that "there is no substance." Nothing has a fixed, permanent existence. Many years ago, a scientist friend from Russia explained to me the basics of particle-wave theory, i.e. that energy and matter are actually the same stuff - depending on how you observe it, it can exist as a particle (matter, i.e. form) or as a wave (energy, i.e. emptiness). I'm not a scientist, so I may not have that down quite right, but this is one interesting way that some people have explained the Heart Sutra.
If this is where it ends, though, I think it's missing something. I read a book in Japanese, Hanya Shingyo No Shinjitsu about just this thing: the standard interpretation is lacking. It's a scripture, right? If it doesn't speak to the human heart, if it's merely about the external state of things, then it might as well be a term paper (albeit a mysterious and poetic one, with no citations). The author's main point is that "Kuu (emptiness) is the mystical world, the true reality in which there is nothing born, nothing destroyed, nothing stained, nothing pure, no increase, and no decrease - the eternal, unchanging world..." (my translation). It's true that the transient nature of things, the "no substance" part does get a bit of it, but the aspect of what I would call the spiritual world is essential to getting what the sutra is saying. Both Buddhism and Christianity understand there to be a spiritual, or invisible dimension to reality. Even if you don't want to go that far yourself, just consider the human mind. It's something that we know to exist, but we can't grasp it, and we can barely even study it. We can study the mind's expressions and phenomena, but we can't study the mind itself. That's why behavioral psychology, to fans of more "spiritual" psychologies like psychoanalysis and Jungianism, looks quite lacking. It only studies what can be concretely observed. The observable world and the spiritual / mystical (invisible) world, however, are not two, says the Heart Sutra. As a Christian, I agree. In "Practicing the Presence of God," we see how Broher Lawrence brought spirituality into everything that he did. Washing the dishes can be an act of worship, going to bed an expression of eternal love. But I digress.
Form is emptiness, and emptiness is form. Kukai, the founder of the Japanese Shingon sect of Buddhism, explained it using two metaphors: The non-separateness of water and waves, and the non-differentness of gold and crown. Emptiness is the water, form is the wave. The wave comes and goes and changes in appearance, but the water always remains. Again, if a crown is made of gold, the gold is not different from the crown itself. The crown is made of gold, yet the gold itself (emptiness) is the crown (form). Before we go more deeply into this, we're going to back up a little and look at the Heart Sutra's background.
What was the Buddha talking about in the first place? His first collection of sermons talk about the four noble truths, how dissatisfactoriness / suffering comes from out craving / desires / clinging. He also talks about how suffering arises from ignorance, and how the suffering we create for ourselves is all part of a cause-and-effect chain. For example, let's take addiction (to alcohol, sex, particular relationships, drugs, sugar, or what have you). You want to stop doing x, but you can't. As you learn to be vulnerable about talking about x, you find friends who will listen and relate to you without judging. This helps you shed some of the shame that was feeding the behavior. As you talk, meditate, and pray, and begin to see more deeply, you realize that you were seeking rest or comfort in something that was not actually giving you rest or comfort. You then begin to change the way you live, and the way you believe. You replace the belief that "x will give me rest or comfort" to "I am looking for rest or comfort, and I crave x, but I know that x will not provide it." And you begin to feel the feelings that you were trying to avoid with x. You begin to notice when you feel tired, and instead of diving into your work, you learn to take naps in between. You begin to notice when you feel lonely, and instead of running from it with x, you just let yourself feel it. You learn that it's not shameful to cry, and you let yourself cry. You begin to find the comfort and rest you were craving in other ways as well - through genuine connection with others and with yourself. Maybe you change jobs, and take more fulfilling work for less pay. Maybe you sell your extra car to accomodate this. The problem seemed to be your addiction to x, but it was actually much deeper than that - a chain of actions and reactions stemming mainly from wrong beliefs that you had about "the way things are," about yourself and how you ought to act.
The Heart Sutra says that both form and consciousness are empty. It's really talking about the above. The Heart Sutra is giving us the most essential piece of the above process, the root of things. So, in the sutra, Kanon Bodhisattva, in deep meditation, realizes that everything is empty, and procedes to say that form is emptiness and emptiness is form. Above, our addiction came from our desire for rest and comfort. The desire, however, was misdirected to something that could not provide rest or comfort, so it caused suffering for ourselves and for others as well. Our focus on x, not to mention the resulting shame, kept us focused on ourselves, keeping us from intimacy with ourselves and others, sapping our creative energy and depriving the world of the gifts we have to offer. If we apply the second noble truth, we could say that the suffering we were involved in was caused by our desire. If we know from the start that all the things we are attached to are empty, we might realize that our looking for fulfillment (comfort, rest) in temporal things would never come to anything. All temporal things are empty - they won't give you what you're looking for.
If you think about it, this is what zazen or mindfulness practice cultivates as well. It's about non-attachment. You watch your thoughts, and learn not to cling to them. I don't think this means that you let all of your thoughts go, or become completely blank in your mind; you just learn to be flexible and present. You learn to be present to what's important. You learn to let go of your false self, the self that thinks it can find fulfillment in temporary things. "Not this, not this," you say. This is empty, and that's empty, too. Your clinging to your conception to yourself as "good"? Empty. Let it go. Your resistance to being vulnerable and showing your faults to others? Empty. Your clinging to x? Empty, of course, but you already knew that. Knowing that everything is empty seems to be the root of things - but that's not the end of the story.
Until now we have been focusing on the way that form is emptiness. I'm taking this to mean basically the same thing that the writer of Qohelet (Ecclesiastes, or "The Preacher") meant by "Vanity of vanities, all is vanity!" In many Japanese translations of the Bible, by the way, the same character for emptiness (空) in the Heart Sutra is used here for "vanity." This is no mistake.
Ecclesiastes is traditionally believed to have been written by Solomon, the wisest person who ever lived. It is also the most Buddhist-sounding book in the Old Testament. Solomon reveals his heart of wisdom as "Empty, empty, all is empty!", and the Heart of Wisdom Sutra says the same: "Everything is empty!" Isn't that neat? If you end there, however, you end up with mere nihilism, perhaps. Neither faith, however, is nihilistic. Realistic, but not nihilistic. Facing reality can be difficult, which is why it leads to nihilism in some people, but it need not be that way. Facing reality in truth can also be a way to find true hope - and what good is hope if it isn't grounded in reality?
Solomon goes on to tell how he has tested all sorts of things, and found them to be empty. He tests himself with fleeting pleasures - money, sex, partying, or whatever - and finds them to be empty. He then tries wisdom, and doing good - and finds this to be empty as well. This is not to say that doing good is meaningless; it is just to say that wisdom for its own sake is meaningless. Fools die, and the wise die, and at the end of the day the fool is none the wiser, so why be wise? He also famously comments on the transient nature of things. "For everything there is a time, for everything a season." There is a good deal of wisdom in recognizing things in their times and seasons, and responding appropriately. This is another outpouring of non-attachment - it helps you to be present to things in their season. A very small-scale example would be work. Non-attachment to work means that when your work is over, you stop working. Not only do you stop working, but you stop thinking about work. You come home, and are tired - present to yourself, you notice this and take a nap. Rested, your see that your kids are home from school. Now it's time to be present to them, and with work out of your mind, you can be. If you don't know the truth about your work (that it's empty!), however, you will keep thinking about it, thinking that you have to do more, thinking that you have to milk more meaning and satisfaction out of it, even though they never come, since they are empty as well.
But like I said, "Form is emptiness" is not the end of the story. "Vanity of vanities" is not the conclusion. It's just the starting point. When you realize that everything is empty, you also realize that empty is everything. Let me illustrate.
Rather, let Kukai illustrate. Remember his water-and-waves metaphor? First (First here, anyhow. I don't know that one really needs to precede the other.), in "Form is Emptiness," we talk about how waves are "just water." The waves don't last, so don't get attached to them. Right. But now we feel like the waves are meaningless, and our existence is also meaningless, so we start expressing ourselves in some sort of sub-culture fashion, which is a nice start. But then the next part comes. Emptiness is form! Water constitutes the waves! The water is forever! It never goes anywhere! When the waves go away, they're just returning to the water! Or, looking at the example of the gold and the crown - the crown is gold, and couldn't be a crown without the gold. Gold is intrinsically formless, but it's what give the crown its value. This view now returns things to their proper state. When you look at things from the perspective of selfish attachment, they are empty, and their emptiness is "vanity." You are seeing their transitory nature, but trying to cling to it, causing suffering. So we say, "Form is empty." When you look at things from the perspective of non-attachment, however, you can begin to see them in their eternity, in their freedom, letting them be as they are and interacting with them appropriately. Emptiness is form.
What does this mean? While we were addicted to x, we were trying to find fulfillment / comfort / rest in temporal things. Then we realized that they are all empty, and we began to let them go. We also learned to find fulfillment / comfort / rest in the eternal. This actually did satisfy our cravings. And what's more, we gradually gained the ability to bring that satisfaction back into the world of the temporal. We learned to be vulnerable, and learned that we are lovable even with our faults. We let go of our attachment to seeing ourselves as "good." We then let go of our attachment to others - we stopped trying to control, for example, our wife, to get her to love us. We became free just to love her as she is, in her freedom. She can respond with love, or without it, but we don't take it personally, and we don't demand any particular response. We just love her.
I'm speaking more as a Christian here, of course, though I'm not sure that it's so different from a Buddhist. I, however, can only speak as myself. I do imagine that it would be a great comfort to believe that the people that you love, though they will die, are just going back into the ocean of eternity, and will continue to exist in some sense. Let me get back to Ecclesiastes for a moment, however.
Form is empty, meaningless in and of itself, but forms come from the eternal sea of emptiness. For Solomon, everything is vanity, but "After all has been heard, the conclusion is this: Fear God and keep God's commmandments."
This is the Christian (and Jewish) version of "Emptiness is form." Fearing and obeying God means simply to know and love the creator of the cosmos. Know the true, spiritual, eternal reality, which is love, and bring that eternity into this moment. Recognize it and actualize it here and now. We love because God loved us, and created us for love, to lose ourselves in love, which is eternal. Here, for me, emptiness is something like love. Not empty, clinging love that tries to control things, but free love - a love where I know myself as fully loved, and I know the eternal One who loves me. Freed by love, I love all temporal (created) things in their freedom. Just like God, I love, but do not demand a response. God sends rain on the evil and the good.
One of my teachers once mentioned that he thought the Christian God is masochistic on account of the command to "love your enemy." Why love someone who tries to harm you? If you do it just because you think you have to, then it does end up being masochistic. This is where actual experience comes in. A mere belief that it's good to love your enemy may not be enough to truly love them. Zazen is a practice that gets you in touch with emptiness, with the eternity that is ever-present in all created things. Prayer and contemplation, which can look very similar to Zazen or mindfulness meditation at times, is a practice that brings you into relationship with the eternal, living God. This presence of the eternal is what gives you true satisfaction. This satisfaction - this love, this rest, this comfort - actually changes you.
This is what Christians mean by "sanctification." You spend time with the Holy Spirit, the spirit of Jesus, and you become like him. You stop striving, you let your old, false self die, and your new, true self comes to life. You become love. You love your enemy now because you are love. Love is who you are, and it's what you do, because it's your nature. There's nothing else to do. Your enemy's hatred of you is truly empty, but your love is eternal. Why fight vain empty hatred with hatred, harming yourself and others? You are love, and you love your enemy - and maybe your enemy changes, or maybe not. Either way, you would rather love and be with God than to do anything else. This is a good addiction. This is an addiction to peace that never fails, to love that always fulfills all of your deepest, truest desires.
In the Buddhist sense, "emptiness" as I'm using it can refer both to meaninglessness and to the eternal. In the Bible, it takes on a slightly different nuance, referring mainly to the more negative sense. This is not always the case, though. The hebrew word used in Ecclesiastes is hevel, meaning "wind, breath, nothingness, vanity." Its association with wind is interesting; Solomon often calls vain pursuits "grasping after the wind." You try to hold on to something that can't be held, and it causes suffering. Later, though, the wind metaphor is redeemed. In the book of John, Jesus is talking with a high-ranking Jewish teacher, and says to him that those who are born of the Spirit are like the wind - no one knows where it comes from or where it is going. When your false self is grasping after the wind, it is in vain. When you are "reborn" as your true self by God's spirit, you become like the wind. Now you are not "grasping" after vain pursuits; you are directed by the Spirit, the breath of God. Instead of grasping, you have let go, and found yourself to be grasped by the eternal. Now you are like the wind - ungraspable. Insomuch as you act out of your true nature, nothing can touch you, nothing can steal you away from the grasp of love. Jesus' words here are recorded in Greek, but I wonder if he might have been speaking in Hebrew here, using that very same hevel to refer to the wind. Regardless, since we are using terms like "false self" and "true self," I want to elaborate now on emptiness and the self.
Christians looking at Buddhism often make a mistake here. In Buddhism, Emptiness, as far as the self is concerned, is expressed as no-self. Some think this means that you try to make your mind utterly empty, devoid of all content and personality. This, of course, is not true. The Dalai Lama, in his book Essence of the Heart Sutra, says this:"If we arrive at the knowledge that the self at which we grasp is empty, we may imagine this means that we as individuals with personal identities do not exist. But of course this is not the case... only the self that is being grasped as intrinsically real needs to be negated. The self as a conventional phenomenon is not rejected." No-self simply means that your conception of yourself is empty. Your imagined "good" self that causes you to blame others and avoid responsibility in order to maintain is not real. No-mind means that you enter a state of rest in your mind, where you are not striving. If we were to state it positively, we could say that No-self means the death of your false self and the life of your true self. No-mind refers to your true mind. Emptiness is not the mere absence of everything.
For the Christian, this is analogous to the "old person" and the "new person." "I have been crucified with Christ, and now it is not I who live, but Christ in me." ... "Consider yourselves dead to sin, and alive in Christ." ... "If I do the things that I do not want to do, then it is not I (my true self) who do them, but sin living in me (my false, dead self that I am forcing to come to life again because of false beliefs I hold). Again, with respect to this: "You will know the truth, and the truth will set you free."
Our old self is "sinful." Maybe we need a new word for this. Corrupted? Fallen? Messy? Walking dead? The old self is caught up in what Peter calls "the corruption that is in the world because of evil desires." We escape this corruption by redirecting our desires so that they can be fulfilled - or in Peter's words, "by participating in the divine nature." By spending time in the presence of the living God, our spirits become alive and we start to act like God. Jesus uses the metaphor of birth: you have to die, and then be reborn. The seed falls to the ground and dies, but then a living tree sprouts from it. The old needs to die so that the new can come. Once you know God, you have this dual principle in you: you have an old, dead self, who is still a mess and isn't able to love or even to see straight, and a new self that is infused with the very substance of God, prone only to love. I don't know if the new self of Buddhists is precisely the same thing, but we can at least say that there is something analogous going on here. I think the Heart Sutra invites us to spend time in emptiness, in eternity, and to bring those qualities into the rest of your life. Spend time with emptiness, and your false self melts away. As your false self melts away, your true self finally finds expression in your waking life. You don't need to contemplate the four noble truths anymore. You have their source. I love the Bible, but only insomuch as it points me to the living God. When you spend time with God, you have access to the same mind that produced the scriptures.
I think the same is true once you are "englightened," once you have had an insight into your true nature. Now you have a true self, and a false self. You still have a decision as to which you are going to be at any given moment, but really it's just a matter of faith. If you want your meditation to be effective, you have to sit in faith that, regardless of what you see of yourself, the truth is that you are already a Buddha. You don't have to do anything to become a Buddha. You can't, in fact, change your nature. This is what Mazu Daoyi's famous scene with his teacher Huairang is about. He's trying to sit himself into a Buddha, so Huairang comes and starts polishing a roof tile in front of him. "What are you doing?" asks Mazu. "Making a mirror." ... "You can't polish a tile into a mirror." ... "If I can't polish a tile into a mirror, then how do you expect to sit yourself into a Buddha? You can't whip the cart and expect the ox to move."
Mazu's issue was one of faith. He thought he had to work himself into something new. This is impossible. He then learned to sit in faith, to rest into the fact that he already is a Buddha. Now he can relax. He doesn't need to strive and fight against himself. Rinzai (Linji), who comes several generations after Mazu, says the same thing: "simply don't strive." He stops striving, his mind calms down, and he returns to his true nature. Without this faith, Zazen practice will do nothing for you.
The same is true for Christian prayer. We have a new, spiritual self. Our practice in action is to "live by the spirit" and to put the old self to death (I think, though, we actually have to love our old self to death. Getting mad at your old self will do nothing. Love that crying child in you. Let him finally go to sleep forever. You won't lose him. He'll be re-created through rest and love, through true recreation!). Our practice in prayer is what the writer of the letter to the Hebrews says: "Strive to enter (God's) rest." The one thing we have to strive to do is to stop striving. The letter to the Hebrews is a wonderful treatise on spiritual growth. It assumes "salvation" - that we have decided to follow Jesus, that we have the Spirit of God living in us. It criticizes those who don't grow, though - those who keep repeating the same blunders over and over - sin, forgiveness, sin, forgiveness, as if they have to start from the beginning every time. "You aren't growing because you don't know the truth!" says the writer. You have direct access to God and the divine nature at any time, yet you're running around trying to "make yourself good," floundering like a fish out of water. Stop trying to make yourself better. Enter God's rest, and be re-created. Get back in the ocean. Stop swimming and just float. Strive to stop striving. Stop resurrecting your old, false self. Rest into God. Sink into the divine nature like a rock sinking to the bottom of a pond. Just stop. This is the beginning of all action. The core of it is this: you have to believe that God is already alive in you. You have to believe that there is nothing that can separate you from God. When you pray, rest into that trust. Sometimes our prayer can look just like Zazen - a silent resting into God's presence. I can't say that a Buddhist and a Christian have precisely the same object of faith, and indeed in Buddhism God is not explicity present (though God, I think, is present nonetheless). If there is a difference, it is that the Buddhist sits in faith the she is already a Buddha, and the Christian sits in faith that she is already a true daughter of the living God - not an orphan, and not a child that will ever go unloved, but a child who can never lose her status, who will never be thrown away, and who shares the same nature as her true Father. We don't try to change ourselves into something else. Resting in faith brings us into the reality of our true self.
The Dalai Lama says that if a Christian were to pursue the concept of emptiness too far, she might harm her faith. In Christianity we have a God who, in the Dalai Lama's words, is "not empty." I appreciate this, but I don't know that the difference really rests in emptiness. To me, the difference lies in the explicit belief in Jesus himself. In Buddhism, God is absent (thought I wouldn't say that Buddhism is explicitly atheistic. The question of God simply doesn't arise), and the question of following Christ doesn't arise. And perhaps emptiness does apply to God in some sense. To realize that our concept of God is empty is crucial. Many Christians feel that they have to defend their faith by clever arguments, but that's not the case. Defend your faith by your being. Open yourself to the possibility that you're wrong about God, and even that God doesn't exist - then seek the living God. I'm confident that God is alive because I've been in God's presence. It's like when Walt Whitman talks about qualifications. "You want qualifications? There're right here, in my eyes." (Or something like that.) Be living proof that God is real and alive. Let God live in you, and you won't be worried about proving God's existence any more than you will about proving your own. To meet the living God, you have to realize that the God that you have created in your own image is empty, is not even real.
God corresponds in a sense to Emptiness, if my interpretation above is accurate. God is eternal, and emptiness is eternal. The difference for a Christian is that eternity has a personality, and relates to you directly, not only with feelings of rest, love, and comfort, but even with words.
Zen is highly influenced by Taoism. The concept of the Tao is quite close to God - it is an existence beyond all existence, something from which all being originates. It is present in all existence, yet still exists as things change and come into and out of being. We need to distinguish, in short, between Creator and Creation. Emptiness applies first of all to creation, but not in the same sense to the creator, since the former is temporal while the latter is not. If I can be allowed to say that the truth of emptiness is that temporal things are temporal while eternal things are eternal, then a Christian has no issue with emptiness. Still, it does become a distinctly Christian emptiness, and will have some distinctives from Buddhist emptiness. The biggest is probably in the eternality of the personality, as I mentioned already.
Christian emptiness looks like what is written in the letter to the Philippians. "Have this attitude in yourselves which was also in Christ, who, not considering his equality with God a thing to be weilded forcefully, emptied himself, taking the form of a man, and becoming obedient until death." This goes directly against the force of corruption, or in evolutionary terms, the force of natural selection / survival of the fittest. If you do know who you are - a child of the living God - you don't need to assert yourself forcefully. You can let yourself go. You have already survived, and you will survive. Let go of your own life. When you know that God's life is in you, you don't need to be afraid to die. This is difficult to practice, but it's true. No mere beliefs will get you there. You have to enter into God's presence by faith. Emptiness means what the Psalm says: "God has made us, and not we ourselves." Stop creating yourself, and be created. Emptiness is God's instruction against idol worship. "Don't put your trust or highest value in any created thing." Idol worship means looking to things for fulfillment. It means looking to x to alleviate your craven desires. It means to find your desires fulfilled only in the eternal, in the indestructable love of God.