The ship of Theseus, as a startup

Plutarch tells us the Athenians kept Theseus's ship for centuries, replacing each rotten timber with a sound one, until philosophers argued over whether it was still the same ship.¹ I have been on the deck of that argument for two years.

The planks

It started in December 2024 with a spreadsheet. A manufacturer asked us why their energy costs kept rising, and we answered the slow way: by hand, from first principles, the way you would write a lab report. The answer was good. It also took weeks.

So we built a tool to make the analysis faster, and planned to sell it to installers. Plank one replaced: from consultants to software.

Then we learned that an analysis without measurement afterwards is a promise nobody can check, and that the data we were given was not good enough to make one. So we built hardware, a device that sits on the site and measures what is actually happening. Plank two: from software to hardware.

Then we learned that a good analysis, even a measured one, is not what people pay for. They pay for the outcome. So we took responsibility for the whole process, from the first data to the battery running every fifteen minutes, and tied our income to savings we can verify. Plank three: from product to operator.

Customer, product, revenue model, even the line between hardware and software: replaced. Every time, it felt like starting over.

What stayed

One question survived every rebuild: what does this site actually need, measured, not sold? The spreadsheet answered it badly and slowly. The tool answered it faster. The device made the answer checkable. The operating model made us accountable for it.

That is my answer to Plutarch's philosophers, at least for companies. Identity does not sit in the planks. It sits in the course. A startup that keeps its product and changes its question has become a different ship; one that changes everything except its question is still sailing.

The practical lesson is older than any of us: do the first one by hand.² Not because it scales, but because you cannot know which planks matter until you have carried them yourself.