Where would we be without our blessed acronyms? JND’s and TPT’s dominated the early days of grad school as Al Paivio (affectionately honoured by his students as ‘Mr. C’ — but that’s another story!) hammered the importance of psychophysics into our stubborn wee minds. Who knew that just noticeable differences and two-point thresholds would have spiritual relevance, lo these five decades later.

I floated a tentative experiment of another kind on this sunny, Sunday, March 1st morning: a return to the contemplative ‘said Eucharist’. This, the early, quiet, back to basics service predicated on the little red book (the BCP, not Chairman M’s manifesto) that had caught my attention as I checked in to Salisbury Cathedral in the early 2000’s after my forty-year sojourn in the wilderness. In keeping with everything else that’s gone ‘environmentally friendly’, the green BAS — Book of Alternate Services — is now the text. But it has the same meditative rhythm of its predecessor, crafted some four centuries ago.

Nineteen of us sat dotted around the pews of St. Jude’s. Harry, the celebrant, now in his 80th year, intoned his way thru’ the prescribed liturgy, pausing midway to insert his message for this day in the year’s early Lenten cycle. The annual ‘giving up for. . . ‘ plans had been crafted by most of us mid-week and, being only four days in, were making a serviceable start at sustaining our resolve for another five weeks. The usual candidates, chocolate and alcohol, had been earmarked for varying degrees of abstention ranging from Garrison Keillor’s ‘giving up giving up Scotch’ to flat out temperance; from Oscan Wilde’s proscription of temptation (‘the only way to deal with it, is to give in to it’) to slightly more draconian measures of self-denial.

The central theme of Harry’s text skillfully tied the season to the intention, Lent to temptation. It linked a period of self-reflection, and stock-taking to the scriptural account of the prototypical struggle, pitting the siren song of desire against resistance and resolve — the temptation of Christ.

So what of JND’s and today’s homily? To illustrate the relentlessness, cumulative nature, and subtlety of temptation, Harry introduced a metaphor: ‘the winter birds of Niagara’. This tale, even to a ‘Peninsula boy’ like myself, was news. In the chill months, the walls of mist rising from the Falls freeze, forming the cataract’s signature wintertime ice bridge. It seems that the ubiquitous and legion gulls, in search of a drink and oblivious to the calendar, continue to swoop into the gorge at the base of the rapids for a sip. Each successive dive adds a thin layer of vapour now freezing to the birds’ wings, insidiously building — until threshold is reached. Aerodynamics are trumped by ice and the birds plummet into the whirlpool.

The process is gradual, just barely noticeable at first — until the difference, the threshold between being airborne and earth- (or in this case, water-) bound is met. Harry likens the challenges, the temptations we face and that confront our resolve, to this cycle: a taste (or a sip) here, a keyboard click or a glance there. Building, expanding, displacing until. . .

A second parallel exists and further binds psychophysics to temptation’s prototype. As the story goes, Christ was at low ebb — 40 days of denial will do that! And the antagonist in the narrative applies the ‘layers’ subtly, starting with low stakes, a loaf of bread. What are a few crumbs, no harm here. (Or, if you’re a thirsty seabird, a sip of water.) The game intensifies moving to a literal ‘leap of faith’; and finally, to an ‘all this could be yours. . . ‘ scenario.

What would a good acronym be without an equation to ground it in application? Enter Weber. In this case:

JND = KI

Our ability to perceive a change in any sensory state (sound, taste, illumination, etc.) is a function of a ‘constant’ (K) multiplied by the intensity (I) of the stimulus. Think the irritating neighbour playing his tunes full bore at 1 a.m. He’s asked politely to ‘turn them down’; and straight-facedly maintains that he has — despite your experience that ‘nothing has changed’. The 120 decibel noise ‘objectively’ is now coming thru’ your wall at a mere 115 db. No JND for you! For the neighbour to find redemption (in your view) the amplifier knob would have to read 108 db’s or 120 minus the noise coefficient (.1) times the loudness (120) — before you’re going to invite him over for a beer and, in the spirit of this piece, forgive him.

On the other hand, you’re sitting in a quiet, open-concept office, concentrating. Over a few cubicles, your coworker starts a telephone conversation — a shift from 50 to 60 db — and you notice immediately (50 times .1 = 5 — more than sufficient to hit threshold)

I’ve speculated a bit about the ‘K value’ of temptation. In short, what’s it take for us to notice that we are being tempted. And equally, how ready are we to ignore the ‘thin edge’ — until we’re spinning around in some pretty icy water. No surprise that this ‘coefficient’ will be specific to each of our respective ‘achilles heels’ (our ‘spiritual sensory equipment’) and to the nature (intensity) of the ‘stimulus’. A tiny uptick in something we really crave is all it takes. A truckload of something we’re lukewarm about — no big deal.

For me it raised a couple of awarenesses: Lent as a time to reflect on our particular ‘vulnerabilities’; and a time to fine-tune our ‘sensitivities’. For the thirsty gull, if we can anthropomorphize for a minute, paying attention to water now, in this moment, as less friend and more threat and taking note that it might be time to flip on the de-icers before the next take off. Only 39 days to go . . . with Sunday’s off for good behaviour.