The day my father punched Oswald Mosley,I learnt something profound about life

Just a thought, but if we don't want our national monuments desecrated by malcontents every Mayday, wouldn't it be wise not to make people malcontented? Easier said than done, I know, but we could start with something simple, such as demanding the withdrawal of that ugly Barclays ad trumpeting the advantages of capitalism writ BIG. There are many reasons for abominating this campaign: it is aesthetically displeasing, cacophonous, dinning; it lacks wit; it has Anthony Hopkins in it; it issues from a bank that would be better advised, at present, to do with its body corporate what the ostrich does with its head; it derides modesty and promotes greed; above all it is an incitement to social hatred. Watching this ad on my Bang and Olufsen hasn't so far prompted me to run out into Whitehall with a spray can, but I can see how, in different circumstances, it could.

It costs me to put myself in the position of a protester, a) because I have lived an easy life; b) because I don't care for shaven heads and body jewellery; c) because I am sentimental about policemen; and d) because I am constitutionally prim about demonstrations and never go on them. Aesthetics again, I'm afraid. I don't like the noise. Or the tastes in tailoring of those I'd have to march with.

Where that would have left me had I been around at the time of the French Revolution I am not sure, but I suspect I would have missed it. All to do with the way one's been brought up, of course, though were my father alive he'd say it had nothing to do with him. Peaceful habits I acquired from my mother. From him, had I had the cojones, I could have learnt to scale citadels. Have I forgotten what he did to Oswald Mosley?

My father's assault on Oswald Mosley occupies a strange place in our family history precisely because we are so incorrigibly law-abiding. We knew he was going to demonstrate at a Mosley meet in Manchester, but he had faithfully promised my mother that he wouldn't get into any scrapes because she was the one who had to sew the buttons back on.

The meeting was scheduled to finish at four o'clock and we began to worry for his safety when he wasn't home by six. At what time, we wondered, did we have to start ringing hospitals? We turned to the television to see if there was anything on the news and there he was! - our father, hallowed be his name, pushing his way through a phalanx of Black Shirts, mounting a platform and taking a swing at their Führer.

These days a slow-motion replay would have shown conclusively whether his punch actually landed or not. But then all we had to go on was general impression, and our general impression was that he'd got close enough to scare the Hitlers out of Oswald, but hadn't quite connected. Which may have been why the police detained him but didn't lock him up. There was still something of a fracas about buttons when he finally did make it home, however, grinning sheepishly, like a schoolboy caught playing hookey.

Funny how affecting it is, discerning the child in a parent, or even just hearing of the child a parent once was. My mother recently reminded me of how my father's parents used to tell him that the Passover Service was his birthday party, his date of birth coinciding conveniently (ie economically) with the Last Supper. Only when he was sent to borrow a corkscrew from the Behrenses next door, and saw that they too were throwing him a birthday party, did he discover the ruse. Why is that so upsetting? Maybe it isn't to you. Maybe you have to be the son of the father to feel his boyish anguish keenly. Maybe you need to suffer the strange revolution of experiencing fatherly feelings for your own dad. Whatever the reason, in a fatherly way I would like to have spared him the pain of that deception.

He was 72 when he died, so there was no descent into second infancy. But increasingly it's the boy in him I find myself recalling fondly. He was annoyed with me when I said in an interview that my old bedroom was more a nursery, now that he'd commandeered it to keep his magic tricks in, than it had ever been during my occupancy.

"Didn't like that," he said. But I had meant it more as a jibe against myself, for never having been man enough to risk being a boy, even when I was a boy.

There's self-pity in this, I don't doubt. Part of being a child while you are a man has to do with absent-mindedness, preoccupation, the slippage of an ageing mind. Thus my father had quite simply been alive too long to remember to fold down his collar once he'd done up his tie, or to make certain he wasn't wearing socks which didn't match.

I remain fanatically meticulous about collars - I will die in a good collar - but the other day I noticed only when I got home that I'd gone out to dinner (to dinner, mark you, and with a woman!) wearing one black sock and one navy. I was becoming my father! I was growing old as he grew old, and now the child that's father to the man was beginning to re-surface.

No matter. Nature must mean something by this ordering of things. Little is better than BIG, that's what I think it means.