The concept of “portfolio lives” was advanced about 30 years ago by a management guru to describe fluidity in the labour market and the likely employment patterns of those who would routinely have two or three jobs before they were 30. The Archbishop of Canterbury, like many older people, regrets this loss of job stability, but sensibly recognises that no one nowadays expects to hold a job for life. What is newer, and far more damaging, is the “portfolio society”: the assumption that jobs, friendships, relationships and ties of birth and kinship are all in flux. The short term is now the only term; if things do not work out, the response is to change the people and the pattern. And that, Rowan Williams believes, is profoundly destructive.

In a lucid interview with The Times, Dr Williams condemns this extension of the “portfolio society” to personal life. Individual identity is becoming fuzzier, as people change partners to suit their mood and expectations of happiness. He fears that with short-term jobs and shorter attention spans come also very short-term relationships. And these, he suggests, have less potential than more testing, enduring commitments. “How do you actually build, long term, a life that has three dimensions, which has interiority and resonance?”

“Interiority” is definitely a Williams word, but the Archbishop has put his finger on the nub of social change that is as confusing as it is, apparently, inexorable. He worries that people no longer take time — for others or for themselves. There is an odious impatience, fuelled by a need for instant gratification. He is wrong to be too critical of consumer choice, but right to question whether a supermarket sensibility should be extended to personal life. Such an approach does little to underpin a human relationship, where patience, tolerance, self-discipline and a readiness to endure occasional hardship and misery are all prerequisites.

More than ill-fated sallies into the sands of Iraq or linguistic contortions over gay clergy, Dr Williams here exudes clarity, purpose and sound common sense. The verities of human relationships are issues where guidance, wisdom and experience are needed. The Church has, at times, been overprescriptive; at other moments, and especially recently, it has appeared to abdicate authority by giving in to a kind of laissez-faire theology that devalues values. Dr Williams says in his interview that he was surprised at the “sheer level of attention” to which, as Archbishop, he is subjected. Every pronouncement is studied for nuances, whether political, social or theological. That, however, comes with the job. And it is therefore particularly important that he demonstrate moral leadership by grappling with issues that torment most souls most days.

The difficulty, of course, in initiating any such discussion is one of tone — as he himself recognises. As a man of some humility, Dr Williams has difficulty in magisterial pronouncements. They would suit neither his temperament nor the times. But half-heartedness and hesitancy would be equally inappropriate, and it is reassuring that he is making an effort to make himself understood by using less elliptical English.

It is important that in denouncing current voguish philosophy and reasserting spiritual teaching and values, Dr Williams is unambiguous and forceful. He should not hesitate to say, again and again, what needs to be said until he is heard. His interview today is the kind of venture into the public forum that can only stimulate respect for his important role. Instead of swapping blows in daily political debate, the Church needs to lead the never-ending debate on the human condition.