Bayes' Theorem (with apologies to Chaucer)

The Prior's Expectation (by John Ross)

A Pryor there was, a holie Manne of Virtue;

No Fawlyt hadde he excepting onlye wanne:

Whytche was to tell hymnselve and alle and sundrye

Before Events the Shaype of Thynges to cumme.

He preachyed of Godde's goode Grayce and love of Breatheryn,

And love dydde he a Member of his Flokke;

A Lassye full fayre but modesste in hyr Manner,

Who blushyed redde at Mention of Manne's Cokke.

A Trysste he mayde wanne Day with this fair Maydenne:

Hys Preetexyt was to offer hyr Advyce

On Matters Spyritual and Holy;

But in hys Mynde were Bayese thoughts of Vyce.

On guessynge thysse and to protect hyrre Honnourye

Ye Maydenne sent hyrre Brothyrre in hyrre Steadde

To keype the Trysste and to deyflecte ye Pryor

From that Bayese plannye he habouryed in hys Hedde.

Hyrre brother Nicholas dydde meet ye Pryor

On Night so dark no Lyghte disturbyed ye Eye

It fell to Hand and Lippe for Reconnoytre

And duly didde ye Pryor beginne to pry.

He kissed the Cheeke to fynde hys Lyps on Stubbyle:

Thysse Evydence disturbed hymme butte a jotte.

So solid was hyse pryor Expectation

His Lykliehoode adjusted; not a lotte.

Pursued the Pryor his fixed Whymme with vigour

His Ardour blynded him to what was not.

Poor Nicholas resisted while his Wille held

But finallye accepted he hys Lotte.

So wythe a fervynt Prayer to Kyngdomme cumme,

Young Nicholas did finallye succumbe.

And thus an Expectation a Priori

Wasye in ye End fulfilled: Posteriori.