Chapter 25. Dividing and joining

A working draft, November 2026. This book is being written while The Grove is being built; expect it to change. Checked against the build as it stood on 1 November 2026.

In this chapter

• Why mergers and splits so often go wrong, and what it costs the business and its people
• Why we borrowed the words, and the order of things, from living cells
• How a whole organisation becomes two, how a part buds off, and how a branch is copied to be compared
• How organisations join: staying two, taking one in, or becoming something new
• How an organisation closes in good order, with everything it held handed on
• The one rule under all of them, and why this has to be built before The Grove goes live

Ask anyone who has lived through a merger and they'll tell you how it went. It was announced, not decided. The two cultures were going to come together, and instead one swallowed the other. Half the systems never talked to each other. The people who knew how things worked left in the first year, and the customers noticed before the board did.

Splits go the same way, only louder. A partnership that has grown apart becomes a fight over the client list. A department spun out as its own company finds out, on day one, that nobody decided who owns the website, the van or the contract with its biggest customer.

The sceptic's view is simple: an organisation is one thing, and changing what it is, by halving it or adding to it, is always a wrench. The damage can be managed, never avoided.

Chapter 24 showed how branches inside one organisation are born, split and folded, with nothing dropped. This chapter goes a level up, to whole organisations: how one becomes two, how a part leaves to become its own, how two come together, and how one closes. It's the part of the design we most need to get right, and none of it is built yet. It has to be before The Grove goes live.

What the usual ways cost

The numbers are hard to argue with. Clayton Christensen and his colleagues, writing in 2011, put the failure rate of mergers and acquisitions at between seven and nine in every ten, on more than $2 trillion a year.¹ Most of that money is spent buying something and then losing what made it worth buying.

The reasons are familiar. A merger is decided by a few people, in private, and then done to everyone else. It happens in one go: on a set day the two become one, ready or not. What can't be joined cleanly is joined anyway, or left hanging. And whose way wins is settled by who paid.

A split costs in the same places. The work that sat between the two halves, the customer both served, the shared supplier, the knowledge in one person's head, has nowhere to go. People are sorted into sides rather than choosing. And because the parting is usually a falling out, every shared thing becomes a prize.

The business pays in what leaks away: customers, know-how, months of drift. People pay in uncertainty. For a long stretch nobody knows which side they're on, who they answer to, or whether their work will still exist.

Borrowing from the cell

Living things divide and join all the time, and they rarely get it wrong. A cell about to divide doesn't cut itself in half and hope. It copies its whole genome first, so each daughter gets a complete set. It holds the two copies side by side inside one membrane. And it won't separate until every chromosome is attached to the fibres that will pull it to one side or the other. Biologists call that wait the spindle checkpoint: a single unattached chromosome is enough to hold the whole division.² Only when everything is attached does the cell pinch in two.

Joining has its biology too. Lynn Margulis argued in 1967, against the opinion of her time, that the mitochondria inside our cells were once free-living bacteria taken in by another cell, and that they still carry DNA of their own.³ Her paper was turned down by around fifteen journals before it was published. It's now the textbook account.

So we've taken our words for these changes from biology, and more than the words: the order of things. Copy the whole pattern before dividing anything. Hold the two side by side before they part. Attach everything before anything separates. The words are less familiar than "split" and "merge", but each one says exactly what happens, and none of them sounds like a fight.

Making more

Cell division: one organisation becomes two

An organisation that has grown into two different things can become two whole organisations. Neither is the original, and neither is the leftover. It runs as a cell's division does.

Ready first. There has to be enough for two: enough people for each side's forums to be real, enough work for each to live on, enough money to begin.

The pattern copied whole to both. Each organisation's DNA, its purpose, its branches and its practices, is copied in full to each side, never split down the middle. Each changes itself afterwards, in its own forums, as it chooses.

The sisters, inside one membrane. Before anything separates, the two organisations-to-be live side by side inside the one that's dividing. Each seat is doubled, held by two people, one for each sister. The two in a pair are always two different people. Someone can hold seats on both sides afterwards, but never both halves of one pair, or nothing would have divided. For a while it's still one organisation, with two of everything beginning to work apart. The sisters stay together until every landing is in place, the legal ones included. Up to the moment of separation, it can be called off: one of each pair steps down, and it's one organisation again.

Everything attached before anything separates. This is the checkpoint, and it's all or nothing. Two kinds of attachment are needed. The first is inside: each person in a pair goes with one side; each asset, document, budget, domain and piece of work in hand goes to one side or is copied to both. The second is outside: each customer, supplier, agreement and organisation it deals with is attached to one daughter or both, and told; the front desk, the way in for anyone writing to the organisation, knows where to send them. If one thing inside has no landing, the whole division waits for it.

But nobody outside can hold it hostage. A supplier, a bank or a customer has to agree before an agreement with them moves, and the organisation can't make them. So each outside relationship has a date by which it lands: as the other party agrees, or, if they refuse or stay quiet, with the side that keeps the legal company, since that's who the contract is with. That side can then serve the other by an agreement of their own, or the contract ends where its own terms allow. One silent supplier can't stop a division, or bargain for a better deal by threatening to.

Separation, at once. When everything is attached, one sister moves into a space of its own, with its own front desk and, where it needs one, its own legal form. It's the one step that can't be undone, so it comes last. And it's the first day in law too. The slow legal work, forming the new company, opening its bank account, getting the consents, moving people's employment, is done while the sisters are still together, and the separation happens on the day it completes. Anything still trailing after that is carried by an agreement between the two, never by staying joined.

The body shared roughly, the pattern exactly. Some things copy freely: documents, practices, know-how, the history in the books. Some divide: money, stock, budgets. And some can't be either: a building, a van, a bank account, a web address, the legal company. Each of those goes to one side, with the other getting a settlement, a new one of its own, or shared use by agreement. The legal company is one of them. Both daughters are equally legitimate on The Grove, but in law one company carries on and the other side forms a new one, and the proposal says which. Making both new would mean winding a company up, paying the tax that can bring, and registering everything again. Money and things follow the work that needs them, guided by who has said they depend on what, as Chapter 17 describes.

Neither sister is weaker. Trust is earned in a context, so it can't simply be copied. But a daughter that started with none would have forums with no weight on its first day. So each starts at full weight, from the history the two shared. Among the people who go to each side, the trust they gave each other carries over. What was given to someone now on the other side falls away, and the rest is scaled back up to make a whole. From then on, each grows its own.

Throughout, the organisation stays whole to everyone outside it. Anyone writing in is answered all the way through. And the keys to its outside accounts never leave the operating system's hands: the division happens on the operating system, so they move from one sister's space to the other's without a person ever holding them.

Budding: a part becomes its own

Sometimes it isn't the whole organisation that has grown in two directions, but one part of it. The marketing branch has become a marketing company in all but name. Yeast and hydra reproduce this way: a small copy grows on the side of the parent and pinches off, and the parent carries on as itself.

Budding follows the same steps, for the part. The bud carries the whole DNA, so it starts as a complete organisation rather than a fragment. Only its own seats are doubled, and only where the parent still needs that work done; one of each pair stays to hold it at home. Its people, things and relationships are attached as in a division. And usually there's one new attachment too: an agreement by which the new organisation goes on serving the one it came from. The parent keeps its legal identity and its name.

Budding is also the easiest way to walk off with value: set up the new organisation, take its seats, and send it more than its share. So it carries its own guards. Anyone who will decide who holds a seat in the new organisation stands aside from deciding the bud. A bud carrying more than the organisation counts as material takes the high-impact clocks and the waiting period. And what went, and to whom, is on the record for everyone to see.

Gene duplication: a copy to compare

The smallest way of making more doesn't create a new organisation at all. A branch is copied inside the organisation, and the copy is meant to differ. It's a twin with a hypothesis: two ways of doing the same work, run side by side, judged by a measure the people proposing it set themselves, with a date to look back.

Genes are copied the same way, and biologists have long watched what becomes of the copies.^{4 5} Most often one is lost. Sometimes one takes on a new job. Sometimes the two share out the old job between them. Twins on The Grove end in the same three ways. One is folded into the other, and what it learned goes with it. One becomes a branch with work of its own. Or the two divide the old work, a region each, say. A twin's people are its own, and its seats aren't doubled; a pair of the same people on both would undo the comparison.

Joining

Joining is division run backwards, with one difference: there are two organisations, so both have to want it. Each raises and decides it at its own root. Neither can be joined against its will.

The two patterns have to fit, too. Anything either organisation holds locked to its purpose can join only where the new arrangement honours that lock, so a merger can't become a way of quietly freeing what was locked. And wherever two of a thing meet, two marketing branches, two sets of books, two front desks, they're held side by side as sisters for a while before they become one. Where joining costs someone their seat, they're one of those it affects: they're asked, they can raise a concern, and the floor beneath every member still holds them.

There are four ways to join, from the lightest to the deepest.

Symbiosis: staying two. The organisations stay separate, bound by agreements: services one offers the other, needs one answers, promises kept between them. Lichen is a fungus and an alga living as one without either ceasing to be itself. This is the common case, and it's built: it's how organisations on The Grove work together today, as Chapter 26 describes.

Endosymbiosis: taking one in. One organisation takes the other in as a part that keeps a life of its own, as the mitochondria in our cells keep their own DNA. It becomes a branch, with its own purpose and practices, inside the larger whole.

The biology fits a little too well, so it's said plainly before anyone consents. A mitochondrion can't go back to living alone, and a branch can't leave on its own either: branches aren't sovereign. The organisation that's taken in gives up its say over its own purpose and over whether it leaves. The way back out is budding, decided in the forum it will sit in. The proposal sets this out in three parts, as an export does: if you do this, this is what happens; this is what you give up after; this is what protects you before.

Fusion: becoming something new. Two patterns combine into a new one, and neither wins. A new purpose is drafted together, by people from both, and then approved by each organisation in its own forums. If they can't agree a purpose, they don't fuse. They can still live in symbiosis.

Grafting: a part of one joined to another. One organisation lets a part of itself go, and another takes it in: one organisation selling its marketing to another, say. It's budding and joining in one act. The first decides at its root to let the part go, attaching its people, things and relationships as in budding. The second decides where it lands, in the forum of the branch it will grow from, as any new branch is heard. It carries the same guards as budding. The operating system gives the mechanics, never the terms. What's paid is between the two organisations. People always choose whether to go, as anyone can always leave, and those who go are welcomed into the second organisation, their seats decided in its forum.

Earlier designs had a fifth way, federating: a new shared root above two organisations that each kept running themselves. We've let it go. With each organisation running in its own space, and no separate network holding data of its own, a shared root turns out to be either a fusion or a set of agreements.

Ending

Apoptosis: closing in good order

Some organisations finish. Their purpose is met, or the world no longer needs what they do. Cells have a way of ending that's part of being healthy, not a failure of it. In 1972 three pathologists named it apoptosis, from the Greek for leaves falling from a tree.⁶ A cell that ends this way doesn't burst. It packages itself into small parcels, and its neighbours take them in.

An organisation can close the same way. It's decided at the root, as a high-impact change with the waiting period, and, as with an export, everyone is asked and anyone can raise a concern. Every landing is set out first. Each member knows where they stand. Each customer and agreement is handed on or ended, and told. Each debt is paid and each promise kept or released. Each thing the organisation holds is sold, given or handed on. And anything locked to its purpose goes to another organisation whose purpose honours the lock, never sold off for whoever is left, much as a UK community interest company's remaining assets must go to another body with an asset lock.⁷ Then it winds down, the legal company is wound up, and the record is kept where its members can still reach it.

This has to be built before go-live too, as Chapter 18 says: a company carries on until someone winds it up, so The Grove needs a step that does.

One rule for all of them

Under all of these there's one rule.

Nothing separates or joins until every part has somewhere to go and every relationship somewhere to land. And wherever two of something meet, they're held side by side as sisters before they become one.

Each change is raised and decided at the root of every organisation it changes, by its forum, with the clocks and the waiting period that high-impact changes carry, and nobody can raise it alone or hurry it. Everyone it touches is asked and can raise a concern, and a concern is met by changing the plan. A twin, which changes only one branch, is decided in the forum of the branch it grows from.

None of it can be forced. Nobody can make an organisation divide, and nobody can make one join. If a division can't be agreed, it lapses, and the people stay responsible for what follows. Only as a last resort, where the forum is evenly split and leaving it half done would itself do harm, would a jury drawn at random rule on whether an objection is legitimate, never on who's right.

And the work, the people and the relationships are the point, not the spoils. A division says these streams of work have grown apart. It isn't two teams dividing what's left. People aren't assigned to a side. They choose, and they can hold seats on both.

How this differs from leaving

All of these happen on the operating system. An organisation that divides or joins stays inside it, under its forums, clocks and locks, and its keys stay where the system keeps them.

Leaving the operating system altogether is a different act: an export, the organisation taking everything it owns as a file, to a platform nobody knows. Chapter 27 describes it. The two share the same care. In both, nothing goes until everything and everyone it touches has a landing written down.

How we decided

We began with the word "fork", borrowed from software, and retired it in September 2026, as Chapter 24 tells. Its replacements, "divide", "spin off" and "merge", were accurate, but they sounded like what the sceptic fears. "Divide" sounds like a split down the middle, with someone getting the smaller half. So we went to biology for words that say exactly what happens, and found they brought the order of things with them.

The checkpoint was the biggest choice. Most splits and mergers go wrong at the edges: the customer nobody told, the contract nobody moved, the account one person held the password to. Making the whole change wait until every one of those has a landing is slower. It also means nobody discovers on day one that something was forgotten.

We chose the sisters, two of each seat inside one organisation, over the quicker way of copying everything at once and letting the duplicates step down. In a copy, the same people would decide for both sides, and nothing would make the stepping down happen. With the sisters, the two sides begin to work apart while they're still one, and the division can still be called off.

We decided that nobody outside could hold a division hostage. All or nothing is right for what the organisation can settle itself. Applied to people it can't make agree, it would hand any one of them a veto, so outside relationships land by a date instead.

We decided neither sister would start weaker, and that one would keep the legal company. Both are meant to be whole organisations from the first day. In law, though, the cheapest and cleanest way is for one company to carry on, so that's treated like the van: one side takes it.

We kept the operating system out of the terms. When one organisation sells a part to another, what it's worth is for them, and whether to go is for each person. The system makes sure nothing is dropped and nothing locked is freed. It doesn't set the price.

The biology stays in the book, where it explains. In the app the words are plain: "Split into two", "Spin off", "Try another way", "Work together", "Join them as a branch", "Become one", "Hand over to another organisation", "Close".

What's still open is less than it was, but real. How twins sit beside the bets of Chapter 14. Whether an organisation can pause, lying dormant rather than closing. How closing works when an organisation can't pay what it owes, which needs the law worked out first. And how all of this feels to the people living through it, which no design can answer before it's tried.

What you might take from this

Mergers and splits go wrong when they're decided out of sight, done in one go, and finished before everything has somewhere to go. A cell does the opposite. It copies the whole pattern first, holds the two side by side, and waits until every last part is attached before it parts. And when its time comes, it ends in good order, handing on what it held.

An organisation can change what it is without a wrench, if nothing separates or joins until everything it touches has somewhere to land.

Notes and further reading

On how cells and organisms came to live inside one another: Margulis, L. and Sagan, D. (1986), Microcosmos: Four Billion Years of Microbial Evolution, Summit Books.