Selectors must axe Bell and decide how triumph turned to disaster so quickly.
Anyone who doubts the importance of psychology in sport - especially in sports of long duration such as cricket - cannot have been at Lord's yesterday (Sunday). Various cliches were verified, notably that when you are winning it is hard to do anything wrong: a cliche that, monumentally, did not apply to England.
Psychologists, were any present, could have enjoyed debating whether England were demotivated when they went out to chase a mere 509 to win, or demoralised, or both. Demotivation is the lesser of the two problems: a fundamentally focused England, recognising the improbability of winning or of surviving five sessions to gain a draw, but hoping just to get on with the job in a creditable way and take to Edgbaston the consolation of a few good individual performances in the hope of fighting another day.
Demoralisation, though, would render England largely incapable of those good individual performances: and that was what the packed crowd at Lord's was treated to as the side capitulated to 103 all out, to lose by 405 runs.
And it clearly fed the side's demotivation. What is astonishing is that the same side who surrendered to Australia yesterday had appeared to have a new dawn at Cardiff, winning a remarkable victory.
Most depressing, perhaps, is that this apparent bipolar approach to cricket is provoked by one thing: the outcome of the toss. Whoever got in first on a wicket made docile - we are told - in accordance with England's instructions was going to struggle to lose this match. And so it proved. But if England are going to enter a mental and spiritual decline just because they end up on the wrong side of a toss, they should take care not to prepare wickets that end up compromising their own bowlers more than their opponents'.
England's inadequacy manifested itself long before the afternoon parade of bemused batsmen returning to the pavilion. Steve Smith, whose fifty came in just 43 balls and included eight fours, made a mockery of Stuart Broad, by far the most impressive bowler England fielded. The five-an-over romp of the Australian batsmen suggested a bowling side who had simply disengaged.
Some of us had a bad feeling about what this same lacklustre fielding side would do when they had to bat. We were not disappointed.
Perhaps on Friday, when England's top order slumped to 30 for four, shock and exhaustion might have been to blame. But yesterday, when Jos Buttler went back to the pavilion, caught behind off the first ball from Mitchell Johnson after the tea interval, and England were crippled at 64 for six, there seemed to be no such excuse, only a collective loss of nerve and calm. The shots to which most of the batsmen got out - never mind Ben Stokes's pitiful run-out - were those of men whose minds were elsewhere. When Moeen Ali offered up the simplest of catches a few balls later the diagnosis was categorically confirmed.
Johnson proved he can bowl just as well in English conditions - the most docile of English conditions - as when he tormented and destroyed England down under the winter before last. There is no question but that Australia have considerable talent in batting and bowling - and also in Peter Nevill, their debutant wicketkeeper - but they did, especially yesterday, come up against a particularly amoebic opposition.
For a team to be reduced to 64 for seven on one of the most benign pitches seen in Test cricket is, or should be, truly shocking. And although Joe Root tried to salvage a little pride, and Broad went down fighting, the problem with a side carrying under-performing players is that the additional responsibility of doing the work of more than one man can undermine everyone else.
There ought to be no question of England going to Edgbaston with an unchanged side, because as well as an injection of talent and focus they need an input of what Michael Clarke, the Australia captain, calls "hunger" - a hunger to excel and a hunger to win.
If the home authorities are going to make the mistake of having a pitch prepared at Edgbaston similar to the one that undid their bowlers at Lord's, then they had better find a proper spin bowler and stop relying on Moeen and Root. But, above all, they need to sort out their upper order.
Adam Lyth has had a dismal series but it would seem cruel, and quite possibly counterproductive, to ditch him now. He needs one more match - provided, that is, he, his captain and the selectors feel he has the psychological solidity to make the most of the opportunity this would give him. But if he went to Edgbaston in a state of nerves that made it almost impossible for him to do the job of seeing off the new ball - something England desperately need an opening partnership to do - then it is better for him to be sent back to his county to regain his composure, with the promise he remains in the selectors' thoughts. In that case, there is no shame in going back to Nick Compton.
The real weak link is Ian Bell, who, with the exception of a solid innings at Cardiff, has had a grim run this calendar year. Some argue that he should not be dropped on his home ground, but that would, the way things are going with him, only be postponing the inevitable.
Jonny Bairstow, who would represent the injection of talent and focus required, made a hundred for Yorkshire yesterday, and if he is not in the side for Birmingham it will indicate a fundamental failure of the selectorial thought processes.
England's second innings was a profound humiliation, the worse for the batting conditions being so benign. Whether it is repeated later in the series is in the first instance up to the selectors, and their understanding of the psychology of how triumph was turned into disaster quite so easily. For the side who won only a week ago to go down to the fourth heaviest defeat in England's history in the ensuing Test is the most disturbing feature of all.