"The whole human race faces a moment of supreme crisis in its advance toward maturity."  Those words opened the Second Vatican Council’s evaluation of modern warfare.   They might well be applied to the question that Pope Francis is addressing in the forthcoming encyclical on climate change, the environment, and sustainable development. 

The U.S. bishops quoted those words at the beginning of “The Challenge of Peace,” their 1983 pastoral letter on war and peace in an age of nuclear weapons.  Like that pastoral letter, the Pope’s new encyclical is sure to raise once again abiding questions about the relationship of religious authority to disputed matters of fact and public policy.  Once again thoughtful Catholics will have to respond to standard accusations that the Pope has no business speaking about global warming, just as the bishops were said to have no business speaking about nuclear strategy.  And once again Catholics sympathetic to the thrust of the document will have to resist the temptation simply to bash those less convinced with hierarchical authority and papal proof-texting. 

So it might be wise to look back to that earlier letter and consider what was one of the most careful treatments of those questions in any recent episcopal document. 

“Why do we address these matters fraught with such complexity, controversy and passion?” the U.S. bishops asked in 1983. And they answered: “We speak as pastors, not politicians. We are teachers, not technicians. We cannot avoid our responsibility to lift up the moral dimensions of the choices before our world and nation.”

They continued in words as applicable to the planetary environmental crisis as to nuclear war: “The nuclear age is an era of moral as well as physical danger. We are the first generation since Genesis with the power to threaten the created order. We cannot remain silent in the face of such danger.”

But the bishops also clarified from the first that “we want readers of this letter to recognize, that not all statements in this letter have the same moral authority. At times we state universally binding moral principles found in the teachings of the Church; at other times the pastoral letter makes specific applications, observations and recommendations which allow for diversity of opinion on the part of those who assess the factual data of situations differently. However, we expect Catholics to give our moral judgments serious consideration when they are forming their own views on specific problems.”

Later the bishops elaborate on this relationship between principles and applications:

 “This letter includes many judgments from the perspective of ethics, politics and strategy …. We stress again that readers should be aware, as we have been, of the distinction between our statement of moral principles and of official Church teaching and our application of these to concrete issues. We urge that special care be taken not to use passages out of context; neither should brief portions of this document be cited to support positions it does not intend to convey or which are not truly in accord with the spirit of its teaching. …

“When making applications of these principles, we realize - and we wish readers to recognize – that prudential judgments are involved based on specific circumstances which can change or which can be interpreted differently by people of good will …. However, the moral judgments that we make in specific cases, while not binding in conscience, are to be given serious attention and consideration by Catholics as they determine whether their moral judgments are consistent with the Gospel.…

“The Church expects a certain diversity of views even though all hold the same universal moral principles.… We urge mutual respect among different groups in the Church as they analyze this letter and the issues it addresses. Not only conviction and commitment are needed in the Church, but also civility and charity.”