Fair play to Oprah Winfrey. Offered the much-heralded opportunity to get the demon cyclist to tell the truth on her US TV show about the seven successive Tours de France he won between 1999 and 2005, and about whether the authorities were justified in confiscating those titles for doping offences, grand old Oprah didn't waste any time with small talk – or even moonwalk. She got straight in there:

"Did you ever take banned substances to enhance cycling performance?"

"Yes."

"Was one of those substances EPO?"

"Yes."

"Did you use any other banned substances?"

"Yes."

Result, times three.

But Oprah, in the pre-broadcast trailers to her show, had said that Armstrong "did not come clean in the way I expected."

Oprah Winfrey puts the questions to Lance Armstrong

Perhaps that was a reference to a statement of his which followed this startling opening salvo of questions and responses as they sat in front of the camera near the cyclist's home in Austin, Texas: "I looked up the definition of cheat," Armstrong said. "The definition of a cheat is to gain advantage on a rival or a foe. I don't view it that way. I viewed it as a level playing field."

And there it is. The classic doper's defence.

Back in the 1992, a not particularly well-known British discus thrower and shot putter, Neal Brunning, tested positive for testosterone at the National Indoor Championships in Birmingham. "Don't bother to test the B sample," the burly Londoner reportedly said. "I know what's in it." Speaking to Brunning a couple of years later was instructive. He was candid. "I did it because I felt others in my event were doing it," he said. "I thought 'If they can do it and get away with it, then let's have a go.'"

Charlie Francis, Ben Johnson's coach at the 1988 Seoul Olympics where the sprinter was stripped of his Olympic 100 metres title and world record for testing positive, was, for most of his career, an unabashed apologist for the necessity of taking performance-enhancing substances - a coaching version of Brunning. "I'm not going to have my runners start a metre behind," he once said.

Doping is seen in defensive terms by men such as Francis. It's not a case of "take this, it will really get you out there" so much as "take this, then at least those other bastards won't be putting one over on you." Defensiveness, indeed fear, is endemic to doping and its practitioners. Those who endorse doping, and those who embrace it, strive to feel justified, comfortable even, with what they are doing.

Charlie Francis (right) believed doping was essential to performance for all his athletes, including Ben Johnson (left)

Earlier this week, looking ahead to the broadcast of the Armstrong interview, Johnson was interviewed by the Toronto Star for his thoughts on the matter.

The Canadian ex-athlete's advice to Armstrong was candid. "Confess it all, get it out of the way and move on," he said. "People don't like liars - once you tell the truth you can move on."

But how candid is this from a man who only admitted his doping when called to account for himself under oath at the Canadian Government enquiry headed by Chief Justice Charles Dubin the year after his Seoul "triumph"? Especially as, once he had served his ban, he was subsequently banned for life after testing positive once again?

But it was Johnson's response on the overall moral position of the infraction in which he pre-figured that of the disgraced Texan with eerie exactitude.

Ben Johnson in the dock at the Dubin Inquiry

"It's only cheating if you're the only one doing it," said Johnson, who has always insisted that cheating was rampant at the Seoul Games.

"I've been trying to say it for 24 years," said the 51-year-old former sprinter. "Almost every professional athlete does something."

It's the easy and convenient assumption made by those who cheat. And to be fair it is not without foundation. Of the eight men who contested that Olympic 100m final, for instance, five have been involved in doping charges.

And there is plentiful evidence too that many of Armstrong's competitors were indeed doping. At least one rider who finished just behind Armstrong in each of his Tour victories between 1999 and 2005 has since been implicated in doping.

The thing is, the assumption that "they're all at it" is not only the last word in cynicism, it is also tantamount to an annulment of all sporting endeavour. In hard, commercial terms, it fatally erodes the means of generating profit. Because once the public suspect that they cannot trust what they are watching, the spectacle becomes a farce, the interest dies.

On the subject of Armstrong's doping, Winfrey asked: "Did it feel wrong?"

Armstrong's reply: "No. Scary."

"Did you feel bad?"

"No. Even scarier."

"Did you feel that you were cheating?"

"No. The scariest."

To be so inured to wrongdoing is indeed scary. And it is because Armstrong is wrong, and because there are clean cyclists and athletes in elite sport, that he and - more crucially - his mindset must be resisted, uprooted, banished.