Is there any stranger form of public pronouncement, when you really stop to think about it, than the kind of "unqualified apology" just issued by Niall Ferguson, celebrity historian and purveyor of wrong insights, following his remarks about John Maynard Keynes at a conference in California last Thursday?

At first glance, Ferguson's entirely unweaselly statement looks like a model of how a public figure ought to say sorry. If you're going to launch a bigoted and misinformed attack on Keynes for being short-termist because he was gay and childless (and, you know, ideally maybe don't do that?) then surely the best thing to do is to retract it quickly and completely.

After all, everyone hates a non-apology-apology ("I'm sorry if people were upset"), or an apology that starts qualified and only eventually becomes unqualified under intense pressure. Compare Ferguson's statement with the weekend's other big apology, by the media critic Howard Kurtz: it was self-abasing, but it followed an insufficient apology a few days earlier, and it failed to clear up the confusion surrounding Kurtz's departure from the Daily Beast and his involvement with the mysterious Daily Download website.

Or compare it – to pick an example of a much higher-profile scandal than either of these – to Lance Armstrong's comically cynical non-confession to Oprah Winfrey in January. ("I went in and just looked up the definition of 'cheat', and the definition of 'cheat' is…") Ferguson, to his credit, didn't equivocate. He didn't claim he "misspoke". He did what we're always demanding that misbehaving celebrities do: he just said sorry.

Except, now that he's done so, it's immediately apparent that it's almost impossible to believe that he's being sincere.

This isn't only because his previously expressed views predispose me to distrust him, or because the Keynes-as-feckless-homosexual idea turns out to have a long heritage among like-minded commentators. It's also because there's something about "apologising unreservedly" for views you've expressed that doesn't add up.

Let's consider the possibilities here. It's technically conceivable that Ferguson suffers from a mental disorder that causes words to emerge from his mouth that have no connection to his true opinions. It's also technically conceivable that on Thursday, after his speech, he happened to have a conversation in a bar, or pick up a book in his hotel library, that profoundly transformed his attitudes towards gay people or those without children.

But leaving those preposterous scenarios aside, there are really only two options. One is that Ferguson didn't believe what he said, but just says whatever he thinks his audience wants to hear; the other is that he believed it then and still believes it now. Neither of which makes him look especially good.

The same doesn't seem to apply, interestingly, when what's being apologised for is behaviour, rather than beliefs. I have no idea whether Anthony Wiener or Tiger Woods or Eliot Spitzer or Bill Clinton truly felt contrite for their extra-marital adventures, as they claimed. But it's clearly possible to believe that infidelity is wrong, yet succumb to the temptation anyway. You can sleep around, or send photographs of your crotch to strangers on Twitter, then sincerely regret it, in almost the same moment. Short of the sudden-conversion scenario above, can you sincerely hold a belief, then instantly regret holding it, too? That doesn't seem to make sense.

If Ferguson bounces back unharmed from this controversy, it'll be because his apology lets people mentally file the incident away as one in which he "did the right thing". But it'll also be because nobody thinks too hard about the implications of that apology; once you do, it's difficult to conclude that his statement means anything much at all.

Public relations experts like to say that the first rule of crisis management is to get all the facts out, and to take responsibility for what you've done, quickly and completely. Actually, though, the real first rule is: don't say or do stupid or obnoxious things in the first place.