Election hustings at FMQs
There is a famous or, rather, gently notorious essay in literary criticism, entitled "How many children had Lady Macbeth?"
It drew upon the sundry oblique references to childbirth offered by the King's consort in the Scottish Play. "How tender 'tis to love the babe that milks me" etc.
Later, this work was used to lampoon obsessive, minute scholarship which can end up bypassing the inherent glory of poetry, prose and drama.
Perhaps it was the faintly surreal nature of today's exchanges at Holyrood but my thoughts temporarily drifted from the oratory on offer to a long-past seminar at St Andrews during which I was invited to chuckle over the occasional folly of critics.
The reason? Kenny Gibson, he of the SNP, was ruminating about procreation. More precisely, he was asking about Scotland's population and, thus, birth rate.
At which point, he delved into ad lib territory (many parliamentary questions, you will be shocked to hear, are carefully scripted, even the supplementaries).
Mr Gibson said that he exempted the presiding officer from his anxiety about the balance between Scotland's birth and death rates. Why so? Because the PO, Ken Macintosh, has six children.
Pausing only to congratulate Mr Macintosh, First Minister Nicola Sturgeon shifted on to broader ground. It was vital, she argued, to welcome immigrants who made a contribution to Scotland and to help them settle here.
To be clear, this was not in any way a diversionary tactic. It was, rather, the issue Mr Gibson had raised in the first place.
I said earlier that the exchanges were surreal. Perhaps I should amend that comment or indeed withdraw it. You may say that is a U-turn but it is one which, by contrast with those essayed by political leaders, is freely offered and defiantly acknowledged.
Rather, the discourse was unreal. In the sense that it purported to be questions to the first minister - but was, in practice and reality, a hustings session for tomorrow's local elections. Really, it was about Scotland's 32 councils and, of course, the UK general election to come.
However, opposition leaders contrived, with varying degrees of deftness, to elide the distinction, in pursuit of electoral advantage. Me, I blame vaulting ambition which o'erleaps itself.
For the Conservatives, Ruth Davidson produced an iterative list of statistics purporting to represent the extent to which the SNP had failed in education policy. She derided assurances that matters were in hand as "jam tomorrow".
Ms Sturgeon listed the projects under way, including £120m going directly to head teachers. And she brandished a Tory leaflet which, she said, mentioned the SNP umpteen times but education not once. This was reasonably effective, on the day.
Labour's Kezia Dugdale pursued the question of cash. She accused the FM of vacillating on the topic of a 50p top tax rate.
She accused her further of talking a good game during UK elections - then ducking the challenge at Holyrood, where she had power.
With a slightly weary note in her voice, the FM said that she had favoured a 50p top rate for the UK as a whole - but had steered clear in Scotland, following advice that it might cut the Scottish budget by encouraging top earners to flee over the border. Or, at least, to base their tax affairs south of Hadrian's Wall.
Labour, she said, had also favoured an increase in taxation at the basic rate, hitting relatively low earners. Up with this she would not put.
For the Greens, Patrick Harvie essayed a Single Transferable Question, blending education, taxation and political philosophy. Councils needed cash, he said - although he used the word "resources", today's familiar euphemism of choice. That meant higher tax, for higher earners.
Ms Sturgeon noted his party's role in driving up the budget package for local authorities - but said she dissented from the Green perspective over issues such as school governance and testing.
Not all the leaders get a shottie every week. Today, it was Willie Rennie's turn to face exclusion. Undaunted, the Liberal Democrat leader took to the streets and delivered his message anyway, to the effect that the SNP had presided over a decade of failure.
The rest quickly joined him - on the streets, that is. Campaigning. Evangelising. Cajoling.
On with the elections. Plural. And Brexit. And the contention over indyref2. Anyone out there who fears that confusion now hath made his masterpiece? Fret not. What's done is done.