…whatever remains, however improbable, must be an unmanageable number of possibilities.
I relaxed over an episode of Sherlock Holmes on the TV yesterday evening. Not that recent BBC pastiche, but the Jeremy Brett series, which for me is the definitive Holmes. I found, like most of them, that I’d seen it before, but the production and acting are so good it didn’t really matter.
Sherlock Holmes is a classical creation, and so in one sense above criticism – it is what it is (as Paul McCartney said when someone was critiquing the double album: “Hey, it’s the Beatles White Album…”). But looked at dispassionately, the character actually embodies a popularisation of the very worst of Victorian rationalism and reductionism.
Holmes’ ability to solve crimes from the slightest of forensic clues, his authorship of a monograph on different types of cigar ash and so on, are really nothing but a hymn to the unbridled triumph of human observation and reason, albeit a reason not only of unusual acuity, but one aided by cocaine, shag tobacco and the playing of a Stradivarius. The astonishing accomplishments of Holmes actually rely on three assumptions fundamental to the Enlightenment concept of science:
1 – a train of causes will lead inevitably to just one set of outcomes.
2 – human observation is sufficient to assess those outcomes comprehensively.
3 – human reason is sufficient to trace the causal train infallibly back to the original events.
In other words, the Universe is thoroughly deterministic, and human observation and reason thoroughly competent to comprehend it.
Conan-Doyle famously conceived his detective from the example of Dr Joseph Bell, one of his teachers at Edinburgh Medical School, who employed similar careful observation to astound patients and students alike with the details of their occupation, journeys etc. Such careful observation and deduction are indeed useful medical skills – would that they were more widely valued in these days of instrumental diagnosis in lieu of clinical acumen. In the past I’ve not been above impressing patients (aka “giving them confidence”!) by telling them things about themselves before they told me, from observation. But there are very strict limits to this. In Dr Bell’s case it was, essentially, a party-trick – any wrong conclusions would be quickly corrected by the presence of a living patient. There’s a famous anecdote about Joseph Bell (which I believe he himself cheerfully told):
Arent you a bandsman? Dr. Bell asked, standing over the patient.
Aye, admitted the sick-man.
Dr. Bell turned cockily to his students. You see gentleman, I am right. It is quite simple. This man had a paralysis of the cheek muscles, the result of too much blowing at wind instruments. We need only inquire to confirm, Dr Bell said to his students proudly. Now turning to the patient he asked, What instrument do you play my man? The sick-man got up on his elbows, Big Drum, Doctor!
I suspect this kind of thing happened more than once, and even if Joseph Bell was some kind of savant, his imitators were not. The fictional Holmes would never admit to being caught in such error. And yet in the field of crime the dangers of error are even greater: a murder victim cannot correct the detective’s misapprehensions, the criminal does not wish to, and the wrongly accused… well, once he’s hanged there’s no longer any contention. The detective’s reputation becomes self-maintaining.
In the real world, there are countless examples of forensic science over-reaching itself, leading to false convictions. Often, it is still true that one reliable witness more than counterbalances a mountain of microscopic evidence. Fortunately, the field of crime has access to many such witnesses. The sad truth is that reality is not that deterministic – and even where it is, it is usually too complex to be fully encompassed by human observation and reason, even when that is augmented by shag tobacco.
There are at least two, still very active, fields in which the ideals of Sherlock Holmes continue to be over-represented, and hence dangerous to truth.
The first is Biblical criticism. It was a peculiarly Enlightenment conceit to believe that one could take a document like, say, the Pentateuch, and confidently reconstruct from it multiple literary predecessors of which there are no remains and for which there is no historical evidence. It is even more presumptuous to suppose that, from that reconstructed literature, one can resurrect an entire hidden history of Israel. And yet such overconfidence is the foundation on which nearly all Old (and New) Testament scholarship proceeds. And so it is not Victorians, but modern scholars, who will propose that the Pentateuch was clearly written during the Exile by scribes under pressure from King Cyrus to unify the disparate traditions of the two displaced kingdoms into one easily adminstered religion. That, frankly, is Sherlock Holmes building an entire life history from a pile of cigar ash. There are more – one might say infinitely more – possible explanations. As Pekka Pitkänen writes in his article Historical Reconstruction and Old Tesament Studies (unfortunately no longer available online, but I could mail you a copy):
We have demonstrated that the nature of historical reconstructions is such that multiple solutions are possible and that it is not enough to rely on a paradigm, or to establish that a solution is logically consistent and that it covers all of the available historical data. How can one then arrive at the best possible solution to the historical reconstruction problem? It is the opinion of this writer that, at face value, one can never be certain of the correctness of a solution. Rather, selecting a particular solution always involves faith.
But “faith” isn’t a word Sherlock Holmes would be comfortable with. The other field, of course, is evolutionary studies, where living witnesses are even less likely to be forthcoming than in Biblical studies. The Darwinian Just-So story is becoming proverbial, and is based on the same overblown confidence in the determinacy of nature, and the reliability of human observation and reason. But as Dr Joseph Bell discovered, you can’t reliably reconstruct the music of life from a pair of floppy cheeks. Pitkänen’s conclusion is equally true in biology: such reconstruction requires faith, as well as cold reason.