Why Shit Is Better Than Piss

"Where there's muck there's brass." — Yorkshire proverb

A few years ago I started composting properly. Not the sad plastic bin in the corner, but the real thing: layers, carbon and nitrogen, turning it with a fork, sticking my hand in to feel the heat. And somewhere in that process I had a small, slightly embarrassing revelation, which I have been chewing on ever since.

Shit is better than piss.

I don't mean this as a provocation, or at least not only. I mean it as a distinction with real consequences — biological, agricultural, and, as I'll try to show, informational. The difference between these two things our bodies make is not a difference of degree. They are not two flavours of waste. They are two entirely different ontological categories, and we are currently making a civilisational mistake because we have confused them.

Substrate and solvent

Start with what they actually are.

Urine is about 95% water. The rest is mostly urea, some salts, some creatinine. It is, functionally, a solution. Its job is to carry dissolved nitrogen out of a body that would otherwise be poisoned by it. It is fast, it is cheap, it is high-frequency, and it has essentially no structure. You cannot build anything out of a liquid.

Faeces is something else entirely. Depending on who you ask, somewhere between a quarter and a half of its dry mass is bacterial biomass — living and recently living organisms. The rest is undigested fibre, sloughed-off cells, bile pigments, water. It has structure. It has a microbiome. It has, in a very literal sense, a population.

So here is the distinction I want to hold onto:

Piss is a solvent. Shit is a substrate.

A solvent dissolves things. It carries, it disperses, it cleans, it burns. A substrate is something you can build on. It holds. It hosts. Things grow in it.

History bears this out with a clarity that is almost rude. Nobody has ever fought a war over urine. But in the 1860s, Spain, Peru, Chile, Ecuador and Bolivia went to war over the Chincha Islands — three lumps of rock off the Peruvian coast covered in several metres of accumulated seabird shit. The United States passed an entire law, the Guano Islands Act of 1856, authorising its citizens to claim any unoccupied island anywhere on Earth if it had bird droppings on it. That law is technically still on the books. Shit built the nitrogen economy of the 19th century, fed Europe, and caused naval battles.

Piss, meanwhile, had its own industrial career — and look at what it did. Roman fullers collected it in pots on street corners to bleach togas with ammonia; Vespasian taxed it, and when his son objected, held up a coin and said pecunia non olet — money doesn't smell. Later, European nitre beds soaked manure and urine to extract saltpetre for gunpowder.

So: shit makes soil. Piss makes bleach and explosives.

I love that this is literally true. Piss dissolves and detonates. Shit accumulates and feeds.

Even in the garden the asymmetry holds. Urine is a wonderful fertiliser, but you have to dilute it ten to one or it burns the roots off your tomatoes. It's a nitrogen spike — fast-acting, immediately available, and dangerous at full strength. Compost is slow-release. It doesn't just feed the plant, it builds the medium in which plants can be fed. The Amazonian terra preta — dark earths made over centuries from charcoal, bones, pottery and human waste — are still measurably more fertile than the soil around them a thousand years later. That is what a substrate does. It persists. It compounds.

What are we producing?

Now let's do the obvious and switch registers.

We are living through an explosion in human and machine excretion of symbols. More words are produced per day now than in any previous century. And the question I find myself asking about nearly everything I read — including my own output — is not "is this good?" but something more basic and more agricultural:

Is this shit or is this piss?

A hot take is piss. It is high-frequency, low-structure, mostly water, chemically identical to ten thousand other hot takes, and it burns the roots of any conversation it lands on undiluted. It carries nitrogen — there is real urgency in it, real signal — but it has no body. It evaporates. In a week, nothing remains.

A well-composted essay, a working piece of software, a song that took three years — that's shit. Sorry. It's dense. It has bacteria in it: other people's ideas, half-digested, still alive, doing work. It's structured enough to be turned over, moved around, built on. You can put it in the ground and something grows.

The AI question becomes sharper under this frame. I don't think the problem with machine-generated slop is that it's fake. The problem is that it's piss. Enormous volume, high dilution, no microbial life, no fibre. It carries real nitrogen — these systems genuinely know things — but delivered at full strength and at scale, it burns the commons it lands on. We are nitrogen-flooding the informational watershed and then wondering why there's algae everywhere and nothing else can breathe.

Which, note, is not an argument against the machines. It's an argument about what we do with the output. Which brings us to the part everyone skips.

Raw shit kills

Here is the honest caveat, and it's the whole point.

Untreated human faeces is one of the great killers in human history. Cholera, typhoid, dysentery. John Snow and the Broad Street pump. Roughly half a million children still die every year from diarrhoeal disease, mostly because shit gets into water.

So "shit is better than piss" is not "shit is good." Raw shit is a catastrophe. Shit is only better than piss if you compost it. And composting is a technology — a real one, with requirements. You need carbon to balance the nitrogen. You need oxygen, which means turning. You need heat, which means mass. And above all you need time, which is the one input modernity refuses to pay for.

This, I think, is the actual lesson, and it applies far beyond the garden.

The startup gospel of "fail fast" is, for the most part, an instruction to piss. Fail quickly, flush, move on, leave no residue, keep no memory. And it works, up to a point — it's hygienic, it's fast, it prevents poisoning. But nothing accumulates. You get a career of dilute failures and no soil.

The alternative is slower and dirtier: keep the failure. Put it somewhere with a lid. Add carbon — other people's ideas, unrelated reading, time away from the thing. Turn it occasionally so it doesn't go anaerobic and start stinking. Come back in two years and find that it has become the medium in which something else can grow.

Every civilisation that lasted figured out what to do with its shit. Not how to avoid producing it — that's not an option for anything alive — but where to put it, how long to leave it, and how to get it back into the ground. The ones that didn't, died of their own output.

We are producing more now than ever, and we have no compost heap.

What are you doing with yours?