Charles Darwin

He came home from the Beagle in 1836. Two years later, reading Malthus, he found the last link of the argument; by 1842 he had a thirty-five page sketch in pencil, and by 1844 a manuscript of two hundred and thirty pages. He had the answer before he was forty.

And he did not publish it. Not until 1859 — twenty years.

The usual explanation is fear of religious reaction, and some of that is surely true. But list what he actually did in those twenty years and something else appears. He classified barnacles for eight years. He attended pigeon fanciers' clubs in London. He kept pigeons in his own yard.

Why would a man who had sailed around the world spend those years breeding pigeons in a back garden?

How much more, then

Open the first chapter of the Origin and there is no Galápagos. There is no wild nature at all. The chapter is called "Variation under Domestication", and what it is about is pigeons.

He shows the reader this first: the fantail, the pouter and the carrier look like different creatures, and every one of them descends from a single wild rock pigeon — produced by people, in a few centuries, selecting roughly by eye. In the England of his readers, pigeon breeding was a hobby anyone knew about. This was not a claim to be proved; it was something the reader already accepted.

That single step is the structure of the whole book: from the known to the unknown, from the small to the large. What he built in twenty years was not the theory but this ladder. The theory had been ready since 1838.

The eight years of barnacles belonged to the same work. Without having felt in his own hands how hard it is to say where one species ends and a variety begins, he could not write that species divide. He was living through, in advance, every objection a reader might raise.

It was not he who ended the wait. In the summer of 1858 a letter arrived from Alfred Russel Wallace in the Malay Archipelago, asking him to look over some thoughts — and the thoughts were the same conclusion. That July their papers were read together at the Linnean Society; he began writing in haste and published the following November. All 1,250 copies of the first printing were taken by booksellers on the first day.

A man who had delayed twenty years finished the book in sixteen months. And the book was not the great work he had planned but an abstract of it — a fact he regretted for the rest of his life.

The question that remainsIf what he spent twenty years finding was not evidence but an order — how far apart are saying what is true and making it believable?