2022 update
For various reasons my investigations of Larry’s education lost momentum in 2016, but now (Nov 2022, some 60 years later) I’d like to produce the most likely rabbit from the official hat.
An obvious solution to the strange reticence of the TCD authorities, or the apparent deficiency of their record-keeping, is simply that Larry was too unwell psychologically to take his final examinations, or even, perhaps, to complete the courses leading up to the Finals, but would otherwise have been able to do so and indeed to pass successfully.
He was therefore quite possibly awarded an aegrotat degree.
Aegrotat
The term aegrotat (abbreviated as aegrot) is used primarily in the United Kingdom and the Commonwealth of Nations. In the context of British undergraduate degrees a student who is too ill to finish may be awarded an aegrotat degree if the student otherwise would have passed exams or other requirements.
en.wikipedia.org/wiki/British_undergraduate_degree_classification
Aegrotat
An aegrotat (from Latin aegrotat, meaning 'he [or she] is ill') degree is an honours or ordinary degree without classification, awarded under the presumption that, had a candidate who was unable to undertake their exams due to illness or even death completed those exams, they would have satisfied the standard required for that degree. Aegrotat degrees are often qualified with an appended "(aegrotat)".
Following the introduction of current regulations regarding mitigating circumstances, aegrotat degrees are less commonly awarded than they previously were.
Public and grammar school pupils for whom Latin was compulsory a couple of generations ago, would immediately chant inwardly “aegroto, aegrotare, aegrotavi, aegrotatum, to be ill” and maybe even visualise it with a dipthong as ægroto etc.
Those of us of a generation even earlier, whose principal recreation was reading, rather than all the other things nowadays that crusty old dinosaurs like me regularly demonise, will remember 1066 And All That, a wonderful parody of English history tuition, published in 1930, which did for pedagogues what Molesworth did for their pupils. If you too can never remember (or care) who came out top, the Picts, the Scots or the Irish, this is the book for you, because it doesn’t tell you unambiguously either.
Look carefully at the title page.
Was Sellar being pre-modernly ironic? It’s the only instance I’ve ever encountered.
There some other concealed subtleties to this title-page, as Oxford and Cambridge were still the most socially prestigious places of learning in England, and their degrees had to sound appropriately superior with the addition of Oxon or Cantab:
- Oxon is an abbreviation for Oxoniensis, a Latin adjective derived from Oxonia (the invented Late Latin name of Oxford), meaning "relating to Oxford" and here refers to Universitas Oxoniensis.
- Cantab is an abbreviation for Cantabrigiensis, a Latin adjective derived from Cantabrigia (the invented Mediaeval Latin name of Cambridge), meaning “relating to Cambridge” and refers to Universitas Cantabrigiensis.
An extra feature is the “Failed MA”, as MA’s at Oxford and Cambridge (and Trinity College Dublin too) are conferred upon any BA graduate who waits five years or so and then makes application and pays a fee. So to have failed your MA could well imply that you’d failed your BA anyway!
Sellar himself was in fact genuinely awarded an aegrotat from Oriel College Oxford in 1922, though Yeatman exaggerated his own underachievement - when trying to convert his BA from Oriel College Oxford into an MA, he couldn’t find the fee owing to debt.
I’ve rather wandered from the point, as usual, which was simply to state that neither Larry, nor his family, nor Trinity College Dublin, had any need for embarrassment or reticence if my supposition as to an aegrotat award is correct. And he would indeed have been correctly described as a graduate of Trinity College Dublin on the cover and title-page of his book.