An intriguing bundle of manuscript has fallen into my possession by means that I would rather not describe. (Readers who have understood C. S. Lewis’s preface to the Screwtape Letters should have no difficulty apprehending my meaning.) It is indisputably in the handwriting of G. K. Chesterton, and appears to be a hitherto unpublished instalment of detective episodes in the career of Father Brown. These episodes find the good Father in the role of chaplain to a university. The institution is never identified by name, but textual evidence suggests that it was founded in the mid-nineteenth century in enthusiastic conformity to Cardinal Newman’s principles and that by the time at which the stories are set — which seems, mysteriously, to be about a century and a half later — it has made the easy descent from a theocracy to a bureaucracy, and from a foundry for the tempering of liberal intellects to a manufactory for degrees. The title of the collection, just visible beneath many outscorings, is The Exasperation of Father Brown.
The first story in the bundle is headed “The Unexamined Clue”. Sadly, the text is rather fragmentary; I would attempt to fill in the lacunae if I dared, but Chesterton’s style is not easy for a weaker writer even to parody, still less to reconstruct. Nevertheless, the plot is discernable, and I trust that my readers will be interested in a brief synopsis.
The plot turns on the murder of that rarest of creatures, a model student. The victim apparently has everything to recommend him both to his teachers and to his peers: not only a promising mathematician but a diligent and painstaking campaigner for the quality of education, he is especially prominent as the moving spirit behind the student union’s initiatives to involve students more closely in the design of teaching and assessment. Nevertheless, the advanced analysis lecture that he attends that Monday morning towards the end of term is to be his last. Everybody sees him take his accustomed seat in the front row at eleven o’clock, but at noon, when the lecturer calls matters to a conclusion and dismisses the class to lunch, this model student is discovered rigid in his seat with the handle of a kitchen knife protruding from between his ribs.
Examination reveals that the victim could only have been attacked from the front, and that however adept the murderer, the knife must have been driven in with his full weight behind it: a nonchalant passing stab would have been impossible. At the same time, the lecturer is adamant that nobody could have passed in front of him while he was speaking, and over a hundred undergraduates are prepared to swear that they observed nothing unusual during the class.
Suspicion naturally falls first upon the lecturer, but is rapidly dispelled. He is widely known to be an active and enthusiastic teacher, deeply committed to his charges’ education; indeed, during that fatal class he had taken ten minutes to deliver a vigorous and spontaneous account of some fundamental issues related to his topic but lying beyond the limits of the syllabus. As the faculty member given responsibility for new initiatives he had spent much time outside class working with the victim, and he appears thoroughly distraught at the death. Furthermore, his students’ testimony is impregnable, and after attempts to shake it the police conclude, reluctantly, that they cannot all be lying.
Enter Father Brown, who pokes around the lecture theatre in his short-sighted manner, displaying particular interest in the unerased notes left on the chalkboard; who chats in an apparently directionless manner with a number of the students; and is seen strolling with the exonerated lecturer in the little scrubby garden into which the more photogenic students are marshalled once a year and made to sit under trees reading books, for the glory of the prospectus. The lecturer at this point fades from the narrative, but a little while later Father Brown is found discussing the crime with the detective and gently dismantling his hypotheses.
The motive is the easiest part of the case, he explains. You would have me assume that a teacher who was thoroughly committed to his students’ education could have no grudge against a student who was equally committed to educating his peers — but you have failed to understand how such a teacher actually sees the world. How would you expect a priest to respond should one of his congregation stand up in the middle of Mass and declare himself an equal partner in the ritual? — still more, if that parishoner should have donned a shaman’s mask before doing so, and should propose to enliven the service with the most whole-heartedly ignorant invocations of the spirits of the earth and air. No, the lecturer — any lecturer — would have a motive, and a motive easily mistaken for a holy one: to defend his charge from the usurper.
But, the detective protests, no man, however strong his motive, could stab another to death in front of a hundred attentive witnesses without any of them seeing a thing.
In front of a hundred attentive witnesses, perhaps not, Father Brown replies. But what is written here, on the chalkboard, at the very start of that enthusiastic digression of ten minutes? “Non-examinable material.” Was there any spell ever woven with more power to turn a hundred students’ minds away from the front of the lecture theatre — towards their imminent lunch, or their impending exams? Three minutes into his digression, that lecturer could have marched a brass band, with a cavalcade of elephants, across the podium without attracting the slightest attention. And five minutes into it, he could certainly have taken three swift steps towards the front row where his keenest student sat, isolated like all reformers who misjudge their peers’ enthusiasm for reform, and silenced for good the buzzing, biting horsefly that had been about his ears for months.
There is a sense, Father Brown remarks thoughtfully, in which it was peculiarly a mathematician’s crime. For most mathematicians are Platonists at heart; and it was Plato who put into the mouth of his own teacher a very piquant observation concerning the worthlessness of that which goes unexamined.