All right, I confess: I've been listening to the Woman's Hour phone-in again. The subject was women eating too much and getting fat. Except of course it couldn't possibly be put like that. The fashionable word obesity was all the talk.

Getting fat - sorry obesity - was described with horror as if it were some appalling calamity that can strike you down any minute - like a thunderbolt. The first caller set the scene for the whole programme. She was, I must say, very enlightened. That is, she knew that she herself was the reason for her obesity. But I was astonished at what she said next. She said: "I know it's eating too much that piles on the pounds. What I want to know is why, when I know this all too well, I still go on overeating?"

Well, darling, St Paul could have told you - in words of one syllable what the presenters of Woman's Hour daren't tell you for fear of political correctness. "The thing you want to do, you don't do; and the other thing you don't want to do, you're doing it all the time". That masterpiece of psychological understanding is straight out of St Paul's letter to the Romans.

Then, on Monday morning on TV, there was this misery guts item about "...people who are affected by eating disorders". Oh come off it. People are not "affected by" eating disorders, they just eat too much or too little or junk food. It's a matter of choice.

But freedom of choice is not restricted to the 200 fat ladies who telephoned Woman's Hour in their distress. This ignorance is all over the place. A boy was stabbed to death at school by a fellow pupil. His mother, understandably driven mad by grief, campaigned for new rules and laws so that, as she said: "This sort of tragedy can never happen again". What she didn't understand was that no new rules and laws could prevent another murder.

Then there was the sickening spectacle of Chris Smith saying that HIV should be regarded "like any other infection". Humbug! It's not like flu or mumps which I might get however I behave. HIV is an infection which, in the huge majority of cases, is contracted by those who choose to live the promiscuous homosexual lifestyle.

Again, the other week there were huge memorials of Auschwitz and I lost count of how many times I heard politicians, radio and television interviewers say that everyone must know what went on in that genocide "so that it never happens again". Are they crazy? Blind? It has happened again scores of times. Millions slaughtered in Rwanda. And in Cambodia by Pol Pot. It is happening now in Sudan. And, terrible though it is to contemplate, it will happen again.

There are terrible incidents in life that we can do little or nothing to prevent - earthquakes, tsunamis, bolts of lightning and so on. But to represent humanity as a pathetic congregation of hopeless victims in those majority of cases where we do have a choice is sentimental and stupid. Worst of all, to take away our personal responsibility in this way diminishes and undervalues us as human beings. Our very humanity consists in having some measure of choice and control over our lives. In short, if I get fat or the pox or a raging hangover, it will be, as they used to say in the Army, "self-inflicted".

* Peter Mullen is Rector of St Michael's, Cornhill, in the City of London, and Chaplain to the Stock Exchange.