As Winston Churchill, Donald Trump, Bill Cosby, or any other of the illustrious names that proudly fill the “success” sections of famous quote websites will tell you, failure is a noble thing so long as you learn from it.

And so we must, on this historically bad day for Labour, be prepared to praise the sheer guts with which it has carried out its immediate and non squeamish post-mortem, and in the full glare of the public spotlight too.

For it has been historic. Indeed, when future historians come to write their many volumes on the mad times in which we now live, I for one hope that at least one in their number has the wisdom to begin their tale on February 23rd, 2017, the day when, as Jeremy Corbyn correctly diagnosed, the people finally rose up against the “political establishment that has let them down” so badly and voted for the Tories.

Only to the superficial does Labour losing a by-election whilst in opposition, in a seat it has not lost in 80 years, appear to be a disaster. In fact, this was the day that Corbyn and his bold new grassroots movement set themselves inexorably on the path to greatness, with such courage and ingenuity in the face of such a setback.

When the Labour leader was asked this morning, hours after losing a seat his party has held for 80 years, whether he “ever wondered whether the problem might be me,” his response was instructive. Lesser men might have reached for the simple answer, “yes”, but Corbyn is courageous enough to hold out and search for the deeper, truer lessons. He gave an equally simple reply: “no.”

Indeed the commendations must be shared around. Well done too to John McDonnell, who within hours of defeat, the wounds still raw, had the wisdom to tour the TV studios and wisely put the blame on “Tony Blair and Peter Mandelson.” Corbyn is an exceptional leader, but no party leader has won a by-election in the same week in which the last-but-three leader from a decade ago has given a speech containing a lone hostile sentence, and that is a rule to which there can be no exception. (Had, in 1996, Michael Foot spoken out against Blair, history might have been very different).

And Paul Mason, too, as awake as ever from the false consciousness that still blinds lesser minds and lesser voters, was absolutely correct in his analysis that “Nobody can claim losing Copeland was Jeremy Corbyn’s ‘fault.’” And indeed nobody has. “The fault,” as Mason correctly attests, “lies with the careerist right-winger (Jamie Reed) who abandoned the seat in mid-session to take a better job.”

And let us not overlook Emily Thornberry, for whom the blame quite rightly lays at the feet of the “fake news” media, for allowing it to somehow “get out” that a man who has campaigned against nuclear weapons and nuclear power for three decades might, in theory, be against the nuclear industry, on which virtually every single job in the Copeland constituency directly or indirectly lies.

When, after 10 to 20 times of asking, Corbyn did commit to “new nuclear” in late January, the fake news media must be held responsible for failing to dedicate the proper resources to ensuring that this single statement was sufficient to overturn with three weeks notice three decades of accumulated campaigning against the very thing that everyone’s livelihoods depend.

Ian Lavery MP, Corbyn’s new campaign chief, wisely deduced that, “This wasn’t in any way, shape or form an election on the leadership of the Labour Party” and that power to supplant himself in the minds of thousands of Lake District voters and correctly conclude that as they made their choice between the two main parties, the leader of one was absolutely in no way a factor, will serve him well in his new job. Doubly so, as he didn’t succumb to the temptation to imagine that the simultaneous result in Stoke-on-Central, in which Labour was not defeated but victorious by a near identical margin, was about anything other than the leadership of the Labour Party.

And there are others who deserve lesser congratulation. The MP Cat Smith should have been brave enough, like the rest, to see that it had even been a defeat, and not labour under the wrong but noble misapprehension that to be 15 to 18 per cent behind in the polls and lose by a mere 2,000 votes is an “incredible achievement” which ranks right up there with Michael Jackson’s incredible achievement in not dropping that baby off that balcony in Hamburg and merely dangling him over for a laugh.