It is not every rugby international across the world who can quote a line from Aristotle, but members of the Irish rugby team have the words of the ancient Greek philosopher on the tips of their tongues.
When I mentioned Aristotle to the retired rugby prop forward Mike Ross this week, he reeled off the quote that sums up the philosophy of the present Irish team: "We are what we repeatedly do; excellence is not an act, but a habit."
Ross and all the members of the Irish team of recent times know this line, because it has been drilled into them by the small-town New Zealand school teacher turned wildly successful international rugby coach, Joe Schmidt.
Schmidt could have it as the epitaph on his gravestone. Under him, excellence in Irish rugby has become a habit.
As the New Zealander announced this week that he will step down as Irish rugby coach next autumn after the World Cup to focus on his family, many in the sporting world and indeed beyond have been left to wonder what the keys are to his success as a manager.
How did the former English teacher with a love of the poetry of Sylvia Plath and WB Yeats inspire a group of young Irishmen to become one of the two best teams in the world, and enjoy continued success?
And are there management lessons for other fields of activity?
Players who worked under him put Schmidt's success down to many factors, and not just his legendary attention to detail.
Players have variously described his training methods on and off the pitch as "tough", "unpleasant", "ruthlessly honest", and even "brutal". But they also laud him as a creative innovator, always prepared to try something new.
In interviews, Schmidt gives little away, for fear of handing any kind of advantage to opponents, merely smiling in his self-effacing way.
As Johnny Sexton remarked in his 2013 book Becoming a Lion: "Joe's got more of an edge to him than his smile suggests."
And Schmidt's rival coach Vern Cotter, for whom he served as an assistant for a number of years in New Zealand, echoed these sentiments: "Joe is a smiling assassin. He seems genial, but there is no one more hard-edged and competitive... He's very, very tough."
He may be tough, but he commands an almost universal respect among the players. He will spend inordinate amounts of time trying to improve each one, by challenging them, pointing out their weaknesses, but also by highlighting their strengths.
In a talk to the charity GOAL, Schmidt revealed that at his famous Monday reviews, he focuses on one thing that a player needs to improve, while also noting two things that the player is doing well. He believes if each individual improvement is achieved, then the team will function better as a unit.
Former player Mike Ross says: "His advice was usually very precise, clear and actionable. It was never vague."
Ross says Schmidt is a believer in the Japanese business philosophy of Kaizen - where performance is improved by the "aggregation of marginal gains".
Tiny improvements can make the difference, and it could be connected to fitness, nutrition, hydration or sleep.
"In top-level sport, what makes a difference is an improvement of 1% or even half a per cent in every little detail," says Ross.
The personalised advice handed to each player goes right back to Schmidt's time as a young school teacher when he spent a year in Ireland with his wife Kellie, gaining overseas experience.
He coached at Wilson's Hospital School in Westmeath and also at Mullingar Rugby Club. His individualised advice to one of the Mullingar players from that time has gone down in local rugby lore: "Do not smoke in the shower."
Schmidt may celebrate the big wins with the team, but only up to a point; it does not take long before he has his eyes fixed on a laptop, analysing each passage of play during the match.
He may watch the match two or three times during the night, and the video analyst is up all night preparing clips for him for further study on Sunday morning.
Tommy Bowe, who played 69 times for Ireland, says: "In some ways there are no secrets to his success. He simply works harder than any other coach out there.
"You could go to the team room at three in the morning to get a snack, and you might meet Joe crouched over a laptop."
He demands strict discipline from his players, and even well-established pros were taken aback by this when he first took over as an Irish coach in 2013, after his successful stint at Leinster.
At one of his Irish training camps, a player dropped their room key in the corridor of a hotel. Schmidt raised the matter at the next team meeting. "Just to let you know, that sort of stuff won't be tolerated. If we're sloppy off the pitch, then we'll be sloppy on it."
Sometimes being part of a camp with the Irish rugby team must feel like being in boarding school, with Schmidt cast as the ever vigilant headmaster.
Mike Ross, who recently published his biography Dark Arts, says: "If you were one of the heavier lads and he caught you going up for seconds at the dessert trolley, he would ask if you really needed it."
He may have a tough reputation, but he also has some managerial quirks and a caring streak that help to pull his teams together.
When he came to Dublin to coach Leinster, he insisted that every player greet every other player by shaking hands every morning.
In a talk at the Pendulum summit, he said he realised that the young boys in the Leinster Academy felt uplifted by this greeting because it showed them that star players like Brian O'Driscoll - who they had always felt were otherworldly - sought them out and shook their hand in the morning. It drew them out, he said, and built up their confidence.
During the same talk, Schmidt quoted Einstein: "Try not to become a man of success, but rather try to become a man of value."
Schmidt may be the most demanding of coaches, but he has managed not to alienate players who have worked under him, an unusual achievement for a disciplinarian. The most obvious reason is that he invests in them personally and has brought them unparalleled success.
Another reason for this is that the Kiwi tends to show loyalty to players even if they may have had a drop in form, focusing on how he can build them back up to peak performance.
"Joe is not a man to discard a tool easily if it has worked well for him in the past," says Ross. "Of course, that is true up to a point - if he gives you an opportunity and you don't take it, you will be dropped."
Those who have served under him also appreciate the way he communicates with players, particularly when he is delivering bad news.
Isa Nacewa, one of his star players at Leinster, once recalled how he informed players who were not picked for a squad.
"It's not a text message, it's not an email, or a voicemail - it's a genuine conversation," he said.
"If he wasn't picking you, and you wanted to know why, he would stay five hours after training to explain."
Those who have worked with him note how he uses his teaching skills to deliver his message about what is required of each player, and from the team.
There may only be three points, because he knows that if there are too many details they will be forgotten. And as a teacher, he knows that it is vital to avoid monotony.
A former school colleague remarked on his coaching skill: "As a teacher... you can't deliver the same style all the time because people stop listening to you, so you have to vary your delivery and he used those techniques in his rugby coaching too."
He believes in learning from other sports and fields of human activity, and earlier in his career as a coach in Ireland, he visited the training ground of Arsenal Football Club and talked to former manager Arsene Wenger and the players. Schmidt asks successful Irish people from different sports and other walks of life to talk to the players. They include the former champion jockey AP McCoy and the historian Professor Diarmaid Ferriter.
"He's a great believer in cross-pollinating ideas, because some of the advice might stick," says Ross.
He has continued the tradition, started by his predecessor Declan Kidney, of inviting Christy Moore to sing for the team - and has even called on the motivational abilities of the comedian Tommy Tiernan.
Michael Kearney, the entrepreneur who worked with Schmidt as manager of the Irish rugby team until 2016, has said that business could learn a lot about management from the coaching techniques of the New Zealander.
In an Architects of Business podcast for the website, Joe.ie, Kearney said one of the lessons business people could learn was the importance of honest feedback.
"One of business' failings is sometimes a lack of that attention to detail and that comes through in terms of maybe managing a multitude of people and giving them honest feedback, and giving them the tools to help make them successful.
"People take on employees and they don't actually give them the time and effort to make them better employees."
The traditions of Irish rugby were built on intensity, fire and brimstone. But Tommy Bowe says that with Schmidt, everything is calculated and thought through.
As one of his players has remarked, some managers get results by fuelling emotion. Schmidt is much more systems-focused. The players talk endlessly about sticking to the process.
But having built a structure and a system and mastered it, Schmidt believes that a team has to allow for spontaneity and innovation. And to illustrate his point, in a recent RTÉ interview, he referred back to his love of poetry.
"You know, people presume there's a lot of structure and there is. I think some of the best poetry I have ever read, it goes beyond the bounds of standard grammar.
"But when you know the grammar really well, you can utilise what you like to get the message across.
"Like when players have a structure, they can go beyond that and play whatever they see in front of them."
When Schmidt's ingeniously planned moves work out on the rugby field, it truly is a wonder to behold - poetry in motion.
And if Schmidt's team lift the World Cup next November, all of the dreams of Irish rugby fans will come true. To borrow a phrase from Seamus Heaney, naturally one of Schmidt's heroes, hope and history will rhyme.
Age: 53 Family: Married to Kellie. He has four children - Abby, Ellen, Tim and Luke. Luke was diagnosed with epilepsy at a young age. Schmidt has spoken out to raise awareness of the condition, working with Epilepsy Ireland on the Be Seizure Aware campaigns. By stepping down as Irish rugby coach next year, he wants to "prioritise family commitments".
Work experience: English teacher at Palmerston North Boys' School; deputy head at Tauranga College; rugby coach for teams in New Zealand, including Auckland Blues Clermont Auvergne, Leinster and Ireland.
Most likely to say: "If you can't turn up, work hard and be a good person, you won't be a good player."
Least likely to say: "Never mind the tactics, just give it a lash!"