Penicillin, X-ray images, artificial sweetener, potato crisps and even Coca Cola were all discovered accidentally, confirming one of Mark Twain’s wisdoms dressed as witticism: “Name the greatest of all inventors — accident.”
There is an unnerving optimism around the hope that great events might be ordered by chance, but as each day passes, it seems more likely that the Brexit standoff might have to rely on one of Donald Rumsfeld’s unknown unknowns for a resolution.
Every rational, achievable option around the backstop and the prospect of a border has been considered and found to be unsatisfactory. There are not, after all, too many ways of securing a frontier between two trading blocks, especially if the free movement of people is a defining difference.
Therefore, yesterday’s suggestion from Britain’s foreign secretary, Jeremy Hunt, that Article 50 may have to be extended to avert a disorderly — the new, slightly sanitised word for disastrous — exit, without a deal, on March 29, is not unexpected.
Indeed, even if it is an expression of the kind of optimism thrashed by House of Commons incoherence and denial, it is welcome and should be facilitated by the EU, as long as Britain can show it has new ideas to discuss.
Mr Hunt and his colleagues must understand, though, that the backstop, or any version of it, must be permanent and legally binding.
The credibility of British politics is at such a low ebb that anything else would be impossible.