In a period of political confusion like the present, it is difficult sometimes to find appropriate expressions to describe what is going on. Discussing this difficulty with a colleague yesterday, I was told that there is a word already in journalistic usage: it is 'omnishambles' - a state of collective disorder, commonly known as a complete mess, which featured originally in the BBC comedy series The Thick Of It.
Nevertheless, in the spirit of linguistic inventiveness, one of my pleasures recently has been to consult the online Dictionary of Obscure Sorrows. For those who haven't seen it, the dictionary tries to capture complex realities for which we do not have terms in English. It does so by inventing words and providing references to the states they describe.
One of those words, I think, explains the Prime Minister's rhetoric before last night's meaningful vote. That word is 'zielschmerz'. It describes an anxiety not only of Brexiteers in Mrs May's own party, but also of Leave voters throughout the country.
'Zielschmerz' is defined as a goal which you reach only to find it is being snatched away from you by your opponents. In the Prime Minister's own words in Stoke on Monday, not to vote for her deal then would mean "to abandon Brexit, betraying the vote of the British people".
The response to that speech by those whom she needed to convince reminded me of another word in the Dictionary. That word is 'paro', defined as the despairing sense that no matter what you do or say, it is always wrong. If any word captures the experience of Mrs May's premiership, then 'paro' is just about perfect.
Of course, there is an Irish connection in all this. It is that other agreement with which the Prime Minister's withdrawal agreement is fatefully linked: the Belfast Agreement of 1998. In this case (mercifully) it is not the specific details of the current backstop which are significant. Rather, it is the shift in expectations that happened in the 1990s and which made that agreement possible.
When Bertie Ahern advised recently that MPs would do well to learn the "realities of Irish history and Irish political affairs", it should have been Mrs May and her advisers who took note. If they had, it would have been clear why her deal was destined for defeat last night. It is a matter of direction and conclusion.
When the peace process was in its early days, the future of Northern Ireland was still being discussed in terms of constitutional options, such as a united Ireland, British-Irish joint sovereignty, even full integration with the United Kingdom. In the course of the 1990s the emphasis changed. Debate shifted from options to procedures. What are the procedures that best secure stability? What are the appropriate strategies to promote trust between political parties? What are the proper arrangements for north-south co-operation?
Of course, that direction simplifies a very tortuous history. Students of Northern Ireland politics would be right to raise all sorts of caveats. Yet, as former Secretary of State for Northern Ireland Peter Mandelson once remarked, the Belfast Agreement became "the only show in town". That was a truism - not because the agreement was the only desirable option, but because it now appeared to be the only conceivable conclusion. For all its limitations, the only show in town was taken for granted, positively or negatively.
It had become the Sherlock Holmes solution. As the great detective told Watson in The Sign Of Four: when you have eliminated the impossible, whatever remains, however improbable, must be the truth. Or politically: that when you have exhausted all other options, whatever remains must be the deal (to which one must now add the rider: the prospect of Brexit that has brought many of the old options back onto the agenda).
Such a direction of political travel would have been the measure of success for Mrs May's negotiations.
Her deal would have ended the debate about options left hanging after the 2016 referendum. It would have shifted focus to how the agreed relationship with the EU would function.
There has been no Sherlock Holmes moment, despite the number of times the Government has stated that its deal really is the only show in town.
On Monday Attorney General Geoffrey Cox repeated that the withdrawal agreement "now represents the only politically practicable and available means of securing our exit from the European Union".
Government whips may have been able to point to some switchers, rather like those sinners who featured in the old travelling gospel missions.
Sir Edward Leigh was one, who called on MPs to repent from "playing with fire", advising them that "the only way to deliver Brexit is to vote for the deal this week" (though he wobbled again in the Parliamentary debate). The number of converts, however, was never sufficient to deliver even a respectable defeat in the meaningful vote.
If the Belfast Agreement was achieved by a shift from options to procedures, the withdrawal agreement really got nowhere. Polls show consistently that under a quarter of the electorate have been persuaded by it.
Among MPs this week (to dip once more into the Dictionary of Obscure Sorrows) any observer would have had the feeling of 'altschmer', defined as weariness with the same old proposals made by the same old people recurring with all the same old flaws and predictable shortcomings.
Speaking this week to the Centre for Policy Studies, Dominic Raab returned to the Global Britain option (some dismiss is it as the Singapore option) arguing that, in "the 21st century, we need to have broader, global, horizons and the freedom to take advantage of the opportunities of the future, from Latin America to Asia".
David Davis raised again the proposition (for which there is no evidence) that the self-interest of member states would overcome a common EU position.
Boris Johnson now made "no deal" the best deal, proclaiming (like F D Roosevelt in 1932) that if "we are brave, we have nothing to fear" from leaving the EU on World Trade Organisation terms.
The DUP, more to the point, was not convinced by the Prime Minister's reassurance about letters from the EU. If Number 10 had hoped for a Dodds domino effect (if the DUP deputy leader could buy into the deal, what Tory wouldn't?) then they were swiftly disabused.
On the other hand, the case for a second referendum has been given legs once more and with cross-party support. Former Conservative Attorney General Dominic Grieve has become the public face of this option. In the Evening Standard (a paper edited by Mrs May's old foe George Osborne), Grieve wrote that leaving the EU is the biggest mistake of recent history and "condemns our country to a third-rate future" which MPs had a duty to prevent. "The proper course of action was further public consultation through a referendum," he argued.
And if the Labour leadership has learned anything from the Belfast Agreement, it is to maintain the option of "constructive ambiguity", allow the Conservatives to take responsibility alone for the omnishambles of Brexit, wait for the Tories to self-destruct and then win a general election. It is not heroic, may ultimately backfire, but it is understandable politics. The common factor in all these options is that none of them acknowledges the Prime Minister's production as the only show in town. Defeat was inevitable. It was only a matter of the size of the defeat.
As the political scientist Philip Cowley noted, the minority Labour Government's defeat in 1924 by 166 votes was the index of the Prime Minister's humiliation.
Last night's Government defeat by 432 votes to 202 has comprehensively rewritten that chapter in political history.
Number 10 will be tempted to respond that "nothing has changed". That is both true and untrue. It is true that we are no further forward. Parliamentary "indicative votes" do not move things on when there is no evident Sherlock Holmes solution (and there isn't). But it is also untrue in that the constitution has now entered uncharted territory, where precedent and convention seem adequate no longer.
The Dictionary of Obscure Emotions has a phrase, of course - 'nodus tollens' - defined as the realisation that the plot of your life doesn't make sense any more. To end on a profoundly sorrowful note, the big danger is that, having failed to plot a course to Brexit and to make that course persuasive, some may conclude that democratic politics doesn't make sense any more.
Arthur Aughey is Emeritus Professor of Politics at Ulster University