Johnny Sexton confronts every contest like a man whose life would be hollow without the song of battle.
rare competitive fury is hardwired into the circuit boards of Ireland's playmaking supernova.
In a bruising, error-laden contest, against opponents who brought an unbending belligerence to Dublin, Andy Farrell's nervy opening night on Broadway was rescued by the 34-year-old out-half's fierce desire to write his own ending.
It wasn't a superlative shift from Ireland's newly installed captain, not one of those rousing State of the Union addresses, but still he proved his team's guiding North Star.
On a desperately jittery Aviva evening, a lethargic home side struggling to shake off those debilitating World Cup pathogens, his interventions were vital.
That and some heroic and defiance late Irish defence with Scotland camped on their line and scenting blood: The outstanding, unbending CJ Stander was the star of the resistance. Josh van der Flier was his prominent lieutenant.
Sexton, returning from a 56-day injury-enforced lay-off, scored a try and summoned his signature precision game, the one too frequently absent in less than stellar 2019.
His initials were on all 19 of Ireland's points – a conversion and three penalties added to his touchdown – denying Scotland an upset their ambition perhaps warranted.
Sexton was vital in preventing his team's frequently out of control galleon from drifting onto the rocks.
Farrell slid into the driver's seat of a stalled Irish motor, one urgently requiring jump leads, a jolt of fresh momentum, a charge of hope after 12 months of unending grimness.
It would be a huge overstatement to suggest that this performance injected the opiate of restored confidence into the veins of a team shaken by their World Cup meltdown.
After all, Ireland, in a rare moment of sunshine in that forlorn Japanese autumn, beat Scotland 27-3.
Here they could score only a single try and hold on by the skin of their teeth against a side they had buried beneath an 11-touchdown avalanche in their last three meetings.
Ireland wheezed and gasped over the course of an asthmatic 80-minutes, Sexton's points along with that rousing late intransigence the inhaler-blast providing some life-saving oxygen.
Had Scotland a little more cutting-edge quality – the kind which Wales will bring to the Aviva next Saturday – and better discipline, they would have snatched a first Dublin victory in a decade.
Their most accomplished player, Stuart Hogg, may succumb to post traumatic stress when he reviews his astonishing failure to ground the ball (using one hand rather than two and dropping it, unchallenged), with a try at his mercy.
In truth, Ireland fell some way short of offering substantial evidence that they can face the future with legitimate cheer.
Not even the 105 days of recrimination and regime change that had unspooled since the crushing loss to New Zealand had entirely washed away the acrid World Cup aftertaste.
Ominously, these 80 minutes sewed as many fresh doubts as they weeded away.
Against low-grade opposition, Scotland, remember, failed to make the World Cup knockout stages, Ireland were laboured, frequently outplayed, disaster averted by exceptional scramble defence and Hogg's brain-fart.
That and the visitors chronic indiscipline.
Joe Schmidt's ultimately suffocating perfectionist zeal is consigned to history; Farrell's challenge here was to liberate and refurbish, to restore the swaggering self-belief of 2018 when Ireland towered at the peak of the European game.
From the start, the masterplan began to fray.
Central to the Farrell makeover was Caelan Doris, a freakishly gifted Mayo born 21-year-old, who, even before his debut, found himself labelled a potential dynasty-maker.
A galloping, unquenchable Number Eight, Doris was charged with arresting the startling downshift in Irish fortunes over a dismal past 12 months.
Sexton led the pre-match rave reviews, the captain's tone suggesting the coltish Leinster phenomenon might yet deliver a dimension which changes everything.
How distressing, then, that the Doris day would last a mere four minutes, a shuddering clash of heads and a failed HIA brutally cutting shot his opening night in green.
If Ireland's World Cup proved a dispiriting, underwhelming, misadventure, Scotland's was a study in sustained catastrophe.
The odds makers deemed Ireland 14 points superior.
Conor Murray, in 2018 regarded as the world leader in scrum half play, had appeared helpless in the face of a precipitous slippage in standards last year.
Farrell stuck with the Munster veteran, resisting the clamour to start John Cooney, such a coruscating presence in the Ulster number nine shirt.
But it was Murray's half-back partner, Ireland's captain and alpha male who answered the emergency call and diverted Farrell's opening night from calamity.