After lecturing in ethics at the Westminster Seminary, I moved on to teach theology at Corpus Christi, an international college. It was there I did the unforgivable: I contradicted the Pope on a matter of ethics.
When Paul VI banned all forms of contraception, I openly disagreed, beginning with personal letters to the London Times and Time Magazine.
Next, I organised a letter to The Times of polite disagreement from the UK clergy. Over 100 priests signed up, but when the hierarchy asked me to defer the letter I acceded to their request.
Meanwhile, they persuaded many of the signatories to withdraw this "terrible insult to the Holy Father". Fifty-five priests stayed with me.
I had no problem with what the bishops did. They run a totalitarian regime in which the Pope has absolute power. I was the one out of line. I warned the remaining signatories we would never have clerical preferment. We'd be lucky to survive.
It was pretty scary switching on BBC radio and finding our Times newspaper rebellion was the first item. But scarier things were to come.
Bishops told us individually to recant. Unless we did, we would lose our present posts. If we continued to disobey, we would have to leave the priesthood. My bishop didn't help by suggesting we repay the costs of our training. I found that a little hard since the most I'd ever earned in 13 years of ministry was £250 a year.
My discussions with Cardinal Heenan were friendly. But he still threatened me. If I openly contradicted the Pope once more I would never have another teaching post in the Church.
I met with him on a regular basis after that, trying to find an accommodation. None was possible, of course.
I was known on radio and for some years had appeared about every two weeks on TV. I gave that all up. If I were asked a straight question about the encyclical I would have to give a straight answer and I'd be finished. I stopped writing books and articles. Inside, I was slowly dying.
I believed then, as now, that the ban on contraception was a disaster. Pastoral experience taught me that it led to marital misery. Most Catholic couples rejected official policy; they respected the Pope but honoured God and their families more.
Two years later when I was finally forced out, I held a press conference in Fleet Street. I said the world population had reached three billion. By 2000, it would be six billion. To think we could stop the nuclear explosion of people by sexual abstinence and the safe period was like suggesting we try emptying the English Channel with a teaspoon.
If the UK abided by Paul VI's principle, by 2000, the population would double. There would be mass unemployment, illiteracy and a break-down of law and order.
Fortunately, common sense prevailed, though not in the Vatican where the ban on condoms remains even for those who are tragically suffering from AIDS after a blood transfusion.
At my last meeting with Heenan, he asked me to go downstairs to see his auxiliary bishop. Victor was a pal of mine. He said he would apply to Rome for my reduction to the lay-state but it usually took two years. I assured him I was in no hurry to be reduced. In the event, it came within a month. Such indecent speed, I thought.
I realised later I could have remained a priest had I merely sexually abused children.
That last time I walked down the steps of Archbishop's House into the London streets, I was 38. I had no money, no job, a few mostly Latin books, a bike, one black suit but no tie.
I felt, however, that I had escaped after 21 years solitary confinement. I was a free man at last.