The Tour de France is a merciless investigator of physical and mental strength. It is subject to the caprices of good fortune and the inevitability of bad luck. Its drama is so overwhelming it has to be cut up and served in slivers. The stage - or etape - is the wonder, anguish and brilliance of the Tour distilled into one-day draughts.
It is the subject of a mesmerising book by Richard Moore, the former Scottish cyclist and now assured chronicler of the sport. He has selected 20 stages with the results not only defining a race but what it means to be a human being placed in the centre of events that strain every sinew and make extraordinary demands on one's emotional and psychological stability.
Moore, who has written four previous cycling books including the peerless In Search of Robert Millar, was careful not to go over old ground in his latest work. There had to be a freshness in material and in approach.
"My criteria for the stages were great, dramatic, mysterious, controversial, terrible, heroic, scandalous, bizarre, tragic - which pretty much sums up the Tour de France," he said. "I picked out some stages that stuck in my mind from watching it as a teenager: one example being Joel Pelier's long lone breakaway and win in Futuroscope in 1989. More specifically, his tears when he was united with his parents at the finish. When I heard the full story, that it was the first time his mother had seen him race because his disabled brother required round-the-clock care, I found it incredibly moving.
"The main challenge I set myself was to get a new interview or interviews for each chapter. So many myths and legends of the Tour are exactly that: myths. Old stories get recycled - even, or especially, the false ones. I wanted to debunk some myths and add a new layer of history to the story of each stage.
"I also wanted to include a range of stages. When people talk about 'great' stages they often mean mountain stages, because this is where the Tour tends to be won and lost. But that ignores great stories about other stages."
The book has insight and revelation. It is also invigorated by anecdote. His favourite story in Etape concerns Jan Ullrich, Bobby Julich and a Tag Heuer watch at the 1998 Tour.
"Here we have the most controversial, dirtiest Tour, where they were all cheating, but I was struck by this vignette: that although both were cheating there was a human bond that formed between them, symbolised by the watch.
"Julich admired Ullrich's Tag Heuer watch during one stage. Ullrich told him he had a spare, and to come to his room one night and get it. Julich felt it would be impolite to do so. But every day Ullrich told him: 'You must come and get the watch'. Finally in Paris, as they prepared to go to their after-Tour parties [Ullrich finished second, Julich third], Ullrich spots Julich in the lobby of the hotel and darts across, saying: 'I will get you that watch'. He disappears up to his room to fetch it. It crystallised the paradox at the heart of the doping issue: that these guys were human, and that they didn't think what they were doing was cheating - they liked each other. They'd have been horrified if they thought they were cheating the other; they gave each other gifts..."
However, Moore does not shy away from the drugs issue and one of the most affecting chapters concerns David Millar, the Scottish cyclist who, on July 13 2012, won the stage from Saint-Jean-de-Maurienne to Annonay. The trip was 266 kilometres but it also served as an emblem of Millar's journey from drug cheat to a clean sportsman who does not deny his past but uses it to point out the insidious dangers of the doping culture.
Moore admits he was "moved" by Millar's victory, adding that the Scot's win can be seen as an attempt to move away from a drugs past that had had a heavy personal impact on the cyclist. He adds, though: "There are cultures where there just isn't the same stigma attached to doping. Alberto Contador's popularity in Spain was never affected by his doping ban. Alexander Vinokourov arguably became even more popular in Kazakhstan, because he was seen as a victim of the system.
"Some of these attitudes persist, which is a problem. Attitudes to doping have changed in some places and are changing elsewhere - but attitudes and behaviour change in different ways, and at different rates, in different places."
There are personalities who have been profoundly affected by the sport. Jean-Francois Bernard, once the great French hope, was so damaged by a stage in 1987 that he never realised his potential. There is an air of melancholy about Bernard to this day but Moore does not believe that cycling must be a route to depression or even that the sport attracts those susceptible to the illness.
"I don't detect any melancholic or depressive streaks in [Bernard] Hinault or [Mark] Cavendish. Hinault especially is not very reflective. He lives in the moment; he raced on instinct His mantra was: 'As long as I breathe I attack'. Cavendish also has that. And Lance Armstrong. Others are more reflective: Greg LeMond, David Millar, Jean-Francois Bernard, Urs Zimmermann certainly. If they have that kind of personality they can have problems because a cyclist has a lot of time to think, and to ask himself questions that might produce difficult answers, or reveal uncomfortable truths - mainly, why am I doing this? From a rational point of view, it's bonkers."
It is also spellbinding, moving and theatre of the most physical and emotionally provocative variety. All the world's a stage. Etape captures the best of them with the heroes delivering the most compelling of lines.
(Etape by Richard Moore is published by HarperCollins at £20)