I came to all of this the way an engineer comes to anything, which is to say badly. I wanted to know which one was correct. I had a row of systems in front of me, the Buddha and Shankara and Ramanuja and the Zen masters, each one calm and certain and contradicting the others, and I treated them like competing specs for the same machine. Surely only one of them could be right about what a human being actually is. It took me an embarrassingly long time to notice that the question I was asking was part of the problem.
Here is the thing that nobody warns you about. Once you read these traditions closely, they stop sounding like rival religions and start sounding like rival answers to one very precise question. And the question is not God. It is you.
Specifically, it is this. When you strip away everything you call yourself, your body, your memories, your running commentary of thoughts, is there something underneath, or is there nothing at all?
Both the Buddhists and the Vedantins agree on the first move, and it is a brutal one. The everyday self you defend all day, the one with your name and your grudges and your plans, is not a fact. It is a construction. A bundle of parts that you have mistaken for a thing. On this they do not blink.
Then they reach the fork, and they part ways so completely that people have been arguing about it for two thousand years.
Non-dualism (advaita)
The claim that reality is, at bottom, not two. Not God-and-world, not self-and-other, not mind-and-matter, but one seamless thing wearing the appearance of many. Almost every tradition in this essay is some flavour of non-dualism. They differ on what the one thing is, and on whether the many are an illusion to see through or a real expression to wake up inside.
The fork
Subtract the self and look at what remains. That is the whole argument, compressed.
Buddhism says what remains is emptiness. Not a void, not nothing in the gloomy sense, but no fixed ground, no unchanging core, no little diamond of pure being at the centre of you that was there before your parents met. There is just process, conditions giving rise to conditions, all the way down. The technical word is anatta, no-self.
Vedanta says what remains is awareness itself. Strip away every thought and you cannot strip away the one noticing the stripping. That witness, silent and contentless, is not your personality. It is the screen your personality plays on, and Vedanta says it is the only thing that was ever fully real. It calls that screen Brahman, and it makes the most audacious claim in the history of philosophy, which is that the screen in you and the screen behind the entire universe are the same screen. Tat tvam asi. You are that.
So one tradition reaches the bottom and finds no floor. The other reaches the bottom and finds that you were the floor the whole time.
The Buddhist answer, taken seriously
The cheap version of Buddhism, the one on tote bags, says everything is impermanent and you should be chill about it. The real version is far stranger and far more rigorous.
Start with three observations the Buddha made about everything you experience. It is impermanent. It cannot finally satisfy you. And nowhere in it is there a permanent self running the show. The person you think you are is a process the way a flame is a process, or a river. The river has a name and a shape and you can point to it, but there is no river-thing apart from the water moving through. Pull the water out and there is no river left over to be sad about. You are like that.
Then, around the second century, a man named Nagarjuna took this and turned it into something close to a logical weapon. His idea was shunyata, usually translated as emptiness, and the precise claim is this: nothing has svabhava, nothing has an own-being, an essence that it carries around independent of everything else. A table is empty of table-ness. Look for the thing that makes it a table apart from its legs and its use and the word we put on it, and your hand closes on air. Everything is what it is only in relation to everything else. Pull on any thread and the whole cloth moves.
What makes Nagarjuna dangerous is his method. For any claim you might make about the ultimate nature of a thing, he denies all four possibilities at once. It is not the case that it exists. Not that it does not exist. Not that it both does and does not. Not that it neither does nor does not. This is the catuskoti, the four-cornered negation, and it is not a trick. It is a machine for dismantling every position you try to stand on, including his own.
This is the part most people get wrong, so it is worth slowing down. Emptiness is not nihilism. Nagarjuna is not saying nothing exists. He is saying that if things had hard, independent essences, nothing could ever change, because an essence by definition does not change. Suffering could never end. The whole point of the path would collapse. It is precisely because you are empty, because you are a process and not a fixed thing, that you are not condemned to stay who you are. Emptiness is the room to move.
There is a second great Buddhist school, Yogachara, that says the world we take to be outside us is closer to consciousness than to matter, more like a shared dream than a collection of objects. And then there is Zen, which is what happened when this whole apparatus travelled to China and met people with no patience for apparatus. Zen keeps the emptiness and throws out the philosophy. A special transmission outside the scriptures, they called it, not founded on words. The koans, those maddening riddles about one hand clapping, are not puzzles to be solved. They are crowbars, designed to pry your conceptual mind off the thing it is clamped to so that you see directly, in a flash they call kensho, what no sentence can hold. Zen is emptiness with its sleeves rolled up.
The Buddhist does not find a true self hiding behind the false one. He finds that the search itself was the last illusion to drop.
The Vedantic answer, taken seriously
Now turn to Shankara, who lived somewhere around the eighth century, and who I suspect would have been a formidable engineer, because his whole system rests on isolating the one variable you cannot remove.
His argument is almost rude in its simplicity. You can doubt the world. You can doubt your body. You can doubt your thoughts, your memories, even the self that seems to be having them. Fine. But notice who is doing the doubting. Awareness is present in every single experience you have ever had, and it has never once been absent. You cannot get behind it to check on it, because the checking is more of it. That ever-present, self-evident witness, the sakshi, is not a thing you have. It is what you are. And Shankara says it is identical with the ground of all being.
Everything else in Advaita follows from protecting that one insight. The world of separate things is real enough to stub your toe on, but it is not ultimately real, the way a rope in dim light is really there while the snake you scream at is not. The snake is a true experience of a false object. Our entire sense of being separate selves in a world of separate things is, on this view, exactly that kind of honest mistake. The cure is not effort. It is seeing. Knowledge alone dissolves it, the way light does not fight the snake, it simply ends it.
I should be careful here, because there is a popular caricature of Advaita as the doctrine that the world is a flat illusion, and good scholarship suggests Shankara himself was subtler than his later followers made him. His own favourite images are gold and ornaments, clay and pots. The ring is not a lie. It is really there, really gold. It just has no existence as a separate substance apart from the gold. That is a gentler and stranger claim than "none of this is real," and it is the one I think he actually held.
Advaita → subtract the self, and awareness is what is left.
Vishishtadvaita → the self is real, a true part of God.
Kashmir Shaivism → that awareness is not still. It vibrates.
Four readings of one experiment. Notice that the gap between the first two is the entire debate, and it comes down to whether the floor of your experience is best called emptiness or awareness.
Why the two look suspiciously alike
If you are squinting by now and thinking these two sound closer than advertised, you are in good company. So did everyone.
Shankara's own grand-teacher, Gaudapada, wrote in a way so saturated with Buddhist logic that scholars still argue about which team he was playing for. And Shankara's rivals had a name for him that was not a compliment. They called him pracchanna bauddha, a Buddhist in disguise. The accusation has teeth. Both traditions dissolve the ordinary self. Both speak of two levels of truth, an everyday one and an ultimate one. Both point past concepts to something words cannot reach.
So where is the actual difference, once you clear away the heat? It is a single word, and the whole disagreement lives inside it. After you have negated everything negatable, the Buddhist says what remains is emptiness, a clearing, an absence of any essence to grab. The Vedantin says what remains is awareness, a presence, the luminous fact that experience is happening at all. One points to the space. The other points to the light in the space. They are standing in the same room, describing it with opposite vocabularies, and each is convinced the other has missed the obvious.
I do not think this difference is merely verbal, though I once hoped it was. A presence and an absence are not the same claim. But I have come to believe the gap is narrower than the polemics suggest, and that a good part of it is a disagreement about where to stop the analysis. The Buddhist refuses to call the final awareness a self, because the moment you name it, the ego sneaks back in wearing a halo. The Vedantin insists you must call it something, because an experience without anyone to whom it appears is a story missing its only necessary character.
The pushback nobody expects
The most interesting objection to Advaita does not come from a Buddhist. It comes from inside the Vedantic family, from a man named Ramanuja in the eleventh century, and it is the objection of someone who found pure non-dualism not wrong so much as cold.
Ramanuja looked at Shankara's world-is-appearance and asked an awkward, almost engineering question about the machinery. This ignorance that supposedly makes the One look like the many, where exactly does it live? Not in Brahman, which is pure knowledge and cannot be ignorant. Not in the individual self, since that self is supposedly produced by the ignorance, which would have the effect creating its own cause. And how can ignorance hide something that is self-luminous, that is by definition the very light of awareness? You do not conceal a lamp by being dark. He had a whole list of these, seven objections in the tradition, and together they press on the softest joint in the Advaita system, which is the strange status of an illusion that is somehow neither real nor unreal.
His own answer keeps the non-dualism but refuses the illusion. Reality is one, he agreed, but it is one the way a living body is one. There is a self, and there are its parts, and the parts are genuinely real, not a misunderstanding to be dissolved. The world and the countless individual souls are the body of God, and God is the soul within them. You are not God in disguise, waiting to wake up and find the world was a dream. You are really you, really distinct, really loved, a true cell in a living infinite. This is vishishtadvaita, qualified non-dualism, and it makes room for the thing Shankara's system has trouble housing, which is devotion, the love between a real someone and a real God.
Shankara offers you the dignity of being everything. Ramanuja offers you the dignity of being something, to someone. It is not obvious which is the greater gift.
The man who stopped arguing
And then there is Ramakrishna, who is my favourite figure in all of this precisely because he refused to do what I spent years doing.
He was a temple priest in Bengal in the eighteen-hundreds, not a scholar, barely literate by some accounts, ecstatic by every account. Where the philosophers argued about the summit, he climbed it by several different routes to see if they came out at the same place. He practised intense devotion to the Mother, Kali, the most personal and dualistic path imaginable, and reached something there. Then a wandering monk named Totapuri taught him formless Advaita, and he reportedly dissolved into the very state Shankara points at, the witness with no second thing in it. He is even said to have taken up the practices of other religions entirely, though the historical record on that is softer than the legend, and to have come out saying the same summit was visible from each.
His conclusion was not a theory. It was four words in Bengali. Jato mat, tato path. As many views, so many paths. He liked to say that the same water is called by different names at different bathing spots on the same river, and that people quarrel over the names while the water does not care. His pupil Vivekananda carried that to Chicago in 1893 and made the West sit up. The lineage that grew from it, the one whose monks I have learned more from on quiet evenings than I will admit in a footnote, holds that Advaita is the highest truth and that the loving, dualist path is no less valid a way to walk there. Not a contradiction. A staircase, and most of us are on a middle step.
Where I actually live
I owe you my own answer, since I promised one, and since the honest answer to "which is most logical" is not a single name.
On pure logical rigour, Nagarjuna wins, and it is not especially close. His position is the hardest to attack because it is barely a position at all. He asserts no essence, no ground, no thesis you can corner him on, so every counterargument slides off. If the game is "never get caught holding a claim that can be refuted," emptiness is unbeaten. The catch is that you win this game by refusing to stand anywhere, and a philosophy you cannot quite stand inside is a strange sort of victory.
On the strength of its single best argument, Advaita wins. The one move I have never seen truly answered is the witness. You cannot doubt awareness, because the doubt is made of it. Every attempt to get behind consciousness and prove it is just chemistry has to be conducted in consciousness, by the very thing it is trying to explain away. That is not a knockdown proof that awareness is the ground of the cosmos. But it is the one fact that survives every demolition, and a system built on the one indestructible fact has something the others do not.
On honesty about the life you actually live, Ramanuja wins. The world does not feel like an illusion when you love someone, or build something, or lose someone. It feels real, and the felt reality of it may be data, not error.
Which leaves the tradition I did not expect to end up in, and the one I now actually inhabit. Kashmir Shaivism takes Advaita's hard non-dualism, agrees that there is one reality and that it is consciousness, and then fixes the thing that always bothered me about Shankara. For Shankara the absolute is perfect and therefore still, and the moving, creating, suffering world has to be quarantined off as a kind of cosmic misunderstanding. The Shaivas refused that. They said the absolute is not a frozen perfection. It is consciousness that throbs, that pulses, that cannot help but express itself, and the name for that pulse is Spanda, vibration. The world is not an error laid over the still absolute. It is the absolute dancing. You are not a prisoner of the dream waiting to wake up. You are the dreamer, briefly and deliberately forgetting, for the joy of remembering.
That, to me, is the most complete picture, even if it is not the most airtight. It keeps the one indestructible fact, awareness. It does not have to insult the world to protect the absolute. And it accounts for the strangest feature of being alive, which is not that we suffer, but that anything bothers to happen at all.
I started this wanting a winner, a single correct spec. I am ending it with something less tidy and, I think, truer. These are not four theories competing to describe one object from the outside. They are four reports from people who went all the way in, sat with the bare fact of their own awareness, and came back trying to say the unsayable in the only words their century gave them. The Buddhist, terrified of the ego's last hiding place, refuses to call it anything. The Advaitin, unwilling to lose the one certain thing, calls it the Self. Ramanuja, in love, calls it God. The Shaiva, watching it move, calls it a dance.
The question was never really which one is correct. The question is which one you can live inside without lying to yourself, and that answer is not the same for every person, or even for the same person in every season. On my hard days I am a Buddhist, grateful that nothing is fixed. On my working days I am a Shaiva, because building anything is an act of faith that the dance is worth joining. And underneath both, on the rare quiet evening when the noise drops out, there is just the witness that all of them were pointing at, and on those evenings the argument seems very far away and slightly beside the point.
They are not describing different summits. They are describing the same summit, and arguing about it, in the only language available at the bottom of the mountain, which is the language of the bottom of the mountain.