Now, it seems, we live in an age where the only truth is a lie. We have no way of knowing whether what the television companies present us with is true or false. The bond of trust has been broken.
The most conspicuous frauds, unmasked last week by The Mirror, are in the confessional chat shows. These are modelled closely on originals drawn from the great wasteland of American television. We now know that in many cases guests laying bare their personal histories were actors and impersonators, and were paid for their lies.
Am I surprised? Sadly, not at all.
The chat shows' carelessness with the truth is the inevitable outcome of a TV culture in which nothing matters but money and ratings. Producers and researchers are under pressure to deliver audiences. Jobs depend on it. Advertisers demand it. And all too often the truth is twisted to achieve it.
Confessional chat shows are hardly creative television. But they harvest the ratings, and are cheap to make. They are often recorded back to back, two or three at a time, in the same studio and in front of the same audiences. All they need is a constant flow of guests with attention-getting tales to tell, usually from the wilder and weirder shores of human relationships. Small wonder that members of the cast of these rolling freak shows are not always quite what they seem.
This is not a personal attack on Vanessa Feltz. I feel for her now. I believe she has been duped. And so has Trisha, over at Anglia Television.
The present scandal has rocked an industry still reeling from the last one. Carlton's partly faked documentary The Connection was exposed as a style of programme-making that would shade whatever truths were necessary to produce what the market demanded.
Viewers are now rightly asking, what can they trust any more? The answer, of course, is: most of what they see. The news, for a start, is widely and rightly trusted. Michael Buerk and Trevor McDonald may not have the full story to hand but they will tell you no lies.
Even news doesn't have a blameless record. I know of one case of simulated news footage, and another, fabricated story about the victim of an earthquake. I told senior executives. None of them wanted to know.
Some time after that, I left journalism, a profession that stands low in public esteem, for politics, which stands even lower.
So what's to be done? The easy answer is that TV must clean up its act. It would be a start if the "great and good" of TV, the veterans of its golden age who are now among its senior executives, were to concern themselves again with the nuts and bolts of programme-making.
TV, like Parliament, can no longer be assumed to be a league of gentlemen. Searching questions - and even offensive ones - will have to be asked, not when a programme is finished, but even while it is being made. There should also be a blacklist of shady producers.
And the Royal Television Society, which confines itself mainly to seminars and the distribution of prizes, could concern itself with these issues of dishonesty that have brought such shame to the medium.
In Britain we used to have the best and most trustworthy television in the world. We can still retrieve it. But we must learn again the most important lesson of all - that programmes always matter more than profits.
Enough sleaze - in TV as in politics.