A friend has suggested I join the Pioneers, whose members abstain from alcohol for life as reparation for alcoholism

I have been thinking (again) about free will. This was stimulated by listening to the BBC Radio 4 programme, Brain Culture. Presented by Mathew Taylor, it gave a riveting example of how our brains can affect our behaviour. A 40-year-old man called Fred, about to start a community sentence for paedophilia, walked into Kansas City Hospital for an MRI scan. The scan showed he had a large tumour compressing his right frontal lobe. When it was removed he reverted to the quiet, law-abiding decent chap he was. Several months later he again began to look at pornography and make lewd gestures towards his step-daughter. Another scan confirmed that the tumour had begun to grow again.

This led to an animated discussion about how free is free will, the legal category of diminished responsibility and whether psychopaths are “bad” or “brain-damaged” (apparently they often are found to be the latter). The pre-frontal cortex is vital to our behaviour, our capacity for self-control; when damaged, the result is impulsivity and a lack of capacity to reflect. Professor Colin Blakemore and Chris Frith, a neuroscientist at UCL, think that more of our behaviour is hard-wired than we will admit; “blaming people” will become less and less meaningful as we gradually reassess the meaning of “a responsible mind”. It was also pointed out that not all paedophiles are found to have brain tumours and that “Fred” had started to act oddly several months before his tumour became serious enough to require an operation.

The Church has always recognised different degrees of responsibility in sin – and that finally “only God can judge”, as they say. I sensed a slight reductive bias in the programme: the implicit suggestion that we are no more than the sum total of our brains, specifically the frontal lobes – those areas memorably excised in the now discredited lobotomy surgery (and I also heard an equally riveting programme about that appalling and barbaric method of quieting down difficult patients on the World Service not long ago.)

While these thoughts were in my mind, a well-meaning friend emailed me to suggest I join the Pioneers – or, to give it its full name, the Pioneers Total Abstinence Society of the Sacred Heart. It originated in Ireland – where else? – and members of the Pioneers abstain from alcohol for life in order to make reparation for those who seem to have no control over their drinking. Having a near relation who is an alcoholic and having several friends whose near relations are also afflicted, I have often participated in conversations about whether alcoholism is an illness with genetic features – or not. I don’t know the answer.

My friend emails: “There has never been a greater need for people to support those who have problems with alcohol in this uniquely Catholic way… It’s such a positive way to show fellowship with our struggling brothers and sisters.” She herself has been a Pioneer for four years and joined up on the Feast of the Immaculate Conception.

This Feast is next week: on Thursday to be precise, when I shall be in Lourdes to celebrate it. Shall I or shan’t I? I look up the Pioneers’ website. Thank goodness, you don’t have to jump into the deep end all at once; it’s possible to make a “limited-period pledge” for a self-specified length of time. I click the button to pay £10, the membership fee, agree to say the Pioneer prayer daily (well, it is a lovely prayer) and to wear the badge – all of my own free will. Only for a limited period, mind. I’ll see how it goes. It’s not that I drink much; the odd glass of wine here and there – and much less than I eat chocolates; but to say “forever” is a grave business and I don’t want to commit myself forever until I am more confident that I will keep the pledge. I’m Irish, after all.