The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.

HISTORY AND THEOLOGY

We have been asking the ecumenically central questions whether-there can be differences of expression of what is, or comes to be-understood to be, the same faith, and, if so, how we can know it to be the same faith. The ecumenical hope rests on the answer ‘Yes’ to the first of these questions, as it does to the central historical question of ecumenism, whether a common faith was shared before our divisions and can be rediscovered and shared again. There are difficulties in establishing the existence of an undivided primitive Church historically. Yet if the evident differences of expression of divided Christians do not somehow express the same faith in the same Christ, there is ultimately no basis for Christian unity. And that applies as much to unity of faith with Christians of other ages as it does to unity of faith among Christians now. So the relation between the history and the theology is crucial.

When those holding seemingly different theologies and using different forms of expression to speak of their faith need to know whether they speak of the same faith, there will almost always be a historical problem to be solved, because the differences will be likely to have their roots in a past division or at least a loss of common context in the past. So the first methodological requirement here is to try to establish a relation between history and theology.

OTHERS AND OURSELVES

‘The thing that separates us most radically from our … brethren is their attitude of mind and ours.’ Ecumenism cannot begin until there can be a shifting of the stances which have made Christians adversaries, and joined them in warfare instead of love. This has to take place both at a personal and at an ecclesial level. The two are intimately interconnected as we shall see in the next chapter. For our purposes in this one, the important thing is to stress the way the divided come to see others as ‘Christians like themselves’. ‘Ecumenism is basically personal relationships … the unity of the Church i s … speeded by wider and deeper personal understanding.’ Cardinal Mercier had already thought of the possibility of Anglican–Roman Catholic talks before receiving the Lambeth Appeal and before Portal or Halifax had approached him with the suggestion which led to the Malines Conversations. In 1919 he went to the USA where he discovered a sense of brotherhood with other Christians, and un vif désir d'unité, and that transformed his view and his priorities.

It is of the first importance to the dynamics that communities seem somehow collectively to feel a rivalry which echoes the personal adversariality and interacts with it in complex ways. Inter-Christian rivalry and competition tempts to proselytising, for example, with implications we shall come to in a moment.

THE RULES

Ecumenical theology has both to look towards and maintain unity; and to counter division. It has in these respects the traditional responsibilities of the theological exercises of earlier ages, when these ‘positive’ and ‘negative’ aspects of the theologian's task were already clear. It also has a third task unique to, and novel in, ecumenical theology. It has to make what appear to be parallel lines meet. It has to make theology done in confessional and ecclesial separation a common theological exercise. This new role will be a principal theme of this study.

It is as controversial in its different way as the two older and more traditional tasks. Ecumenism gets two apparently mutually paradoxical kinds of negative response. The first is really no response at all. It is apathy. Those in the separated churches say ‘We are very well as we are. We have all we need in our church to be Christians together.’ This is of course true. The Church can be fully the Church wherever it is. But it is also obviously the case that something is missing in a Church which cannot feel itself fully at one with other Christians in their communities. The other response is to acknowledge a sense of the threat posed to separate Christian identity by ecumenism.

I shall be arguing that theology done ecumenically is a discipline in its own right, and one whose methods and principles we now need urgently to develop.

At a recent small meeting of representatives from Eastern and Western Europe which was brought together as a forum for the exchange of ideas on European cultural identity I found myself the object of the profound concern of one of the delegates. It was obvious to him that I shared his faith. ‘If you have seen the light why do you not join us?’ he argued. I told him that I did indeed share his faith, but that I did so within the Anglican Church. I should feel equally at home in other churches too. But for me as an individual to become a Lutheran or Roman Catholic or Reformed or Orthodox would not help the cause of unity, because it would do nothing to bring the existing separated churches together. I argued that my job was to stay where I happened to be, and work for the mutual understanding without which there can be no meeting and no convergence. I could, as it were, come alone, or in company, and it seemed to me that Christ's intention is that Christians should meet in company.

From his point of view there was only one true Church and, although I saw it to be the true Church, I was refusing to belong to it. From mine, too, there is only one Church, and I am already in it just as he is. Ecumenists will recognise the encounter. It takes place, with variations, between Christians of all sorts of traditions when they first confront the ecumenical imperative.

FINDING A COMMON LANGUAGE

If Christians are followers of one Christ, the object of the ecumenical common enquiry must be to know him in one faith, but that faith need not necessarily be expressed everywhere in identical terms. There are all sorts of difficulties about the relationship of diversity and variety of expression to unanimity. We shall be looking at these in this chapter. But I want to put forward at the outset the proposition that we are in search of a single Christian truth.

Then we can argue that it has to be grasped in common. That does not mean that everyone has to describe it in the same words. Yet even if distinct languages (in the broadest meaning of the term) remain as theological vehicles, and it is clearly both inevitable and right that they should, it has to be possible to discuss the one truth in a series of sets of words which give everyone a means of expression and access to understanding. The task is to find a way for everyone to be sure that it is the same truth which is being referred to. It is of course notoriously difficult to establish that faith is inwardly identical. ‘Il est impossible d'être absolument certain qu'il existe chez tous une conviction intérieure totalement identique.’

This is a problem which has grown with the spread of the Gospel. In the early Church the language in which formal or official statements were made was at first predominantly Greek, with Latin the second language for these purposes.

The changing scene

Material for ecumenical reception is being published all the time. The appearance of the ‘scene’ constantly changes, under the pressures which have taken us from a sense of wonder at the novelty of agreements which had seemed impossible to a bewilderment at the task of absorbing a veritable stream of such agreements. ‘Bewilderment’ is perhaps the wrong word, because their very multitude is prompting fresh critical appraisal. I will take two examples where this seems to have negative elements.

The first is the two Anglican-Lutheran ‘local agreements’, the Concordat arrived at between the Lutherans and the Episcopalians in the United States of America (LED) and the Porvoo Common Statement of the conversations between the British and Irish Anglican Churches and the Nordic and Baltic Lutheran Churches (1992). They are ‘local’ in that they respond to the special circumstances of the participating churches in the geographical areas they cover. But they deal with Church-dividing issues which are far from local, notably that of the way in which a mutually recognised ministry is to be arrived at. The two texts propose different solutions to the problem of the episcopate. The Concordat proposes a common ministry under parallel jurisdictions as an interim way forward; it suggests the temporary suspension of the Anglican requirement that all ministers should be episcopally ordained. The Porvoo statement attempts a different route, dealing as it does with a group of Lutheran churches some of which, for historical reasons, preserved the ‘historic episcopate’ while others did not.

In his youth Ignaz von Dӧllinger had been a leader of renewal of the Roman Catholic Church in Germany. He also had a strong interest in the institutional growth of Protestantism, and developed friendly relations with Protestants in Germany and outside. After 1850 his work seems more and more strongly marked by his realisation of the value of historical criticism. In Kirche und Kirchen. Papstthum und Kirchenstaat (1861) he argued that churches which separate themselves from the Pope end in chaos. At the same time, he himself was beginning to resist papal claims to absolute power. In 1871, unable to accept the teaching of Vatican I on Papal infallibility, he was excommunicated. Students were forbidden to attend his lectures. He was thus placed in circumstances which encouraged him, although they were personally very painful, to work actively for unity in the Church in such arenas as were open to him.

The protest against the Vatican I decrees in Germany contributed to the formation of the Old Catholic Churches. Döllinger was uncomfortable with anything which would set up ‘altar against altar’, and he found a constructive outlet for his concern in the Bonn Reunion Conferences of 1874 and 1875. These were held under Döllinger's presidency and included Old Catholics who had recently separated from Rome over the decrees of the Vatican Council, German Evangelicals, and a number of Anglicans.

CHURCHES AND PERSONS

It is one of the paradoxes of ecumenical encounter that although what is happening is a meeting of churches, that can happen only in and through the meeting of human individuals. We have already noted that churches are not persons in the same way that individuals are persons, although the Church has a corporate identity as the body of Christ. The problem is that persons do not always keep clear, as they talk, the distinction between their positions as individuals and their positions as representatives of an ecclesial body. ‘I cannot put my name to this,’ says a member of a commission, speaking in conscience as a person, as much as because he fears to ‘betray a constituency’ if he does.

We have not got very far in exploring the relationship between personal change of attitude to other churches and affirmation of mutual respect, and that which is now possible in and between communities; for communities are made up of persons and must carry their members with them when they ‘move’. J. M. R. Tillard writes (in connection with justification by faith) on the ecumenical problem of ‘collective faith’. The bulk of work done over the centuries since Luther has been devoted to the working of justification by faith, in the individual and a Deo solo? But in baptism the candidate becomes a member of the Church.

WHAT IS ECUMENICAL RECEPTION?

Pope Paul VI spoke, in front of the non-Catholic observers at the Second Vatican Council, of ‘the true treasures of truth and spirituality which you possess’. This was an acknowledgement of a need for all churches to address not only ways of receiving and maintaining the common truths of the faith together, but the task of receiving from one another things which each is especially qualified to contribute.

Conversely, reception cannot be complete while separated traditions cling to consciousness of difference of belief. In the 1930s we find ‘The representatives of the Anglican Church would say …’; ‘The representatives of the Eastern Orthodox Church would say … Such assertions can still be heard, as we shall see in a moment. Such clinging amounts to a ‘looking backward to particular traditions’, and that (argues Lukas Vischer), clearly cannot be the last word if we are looking forward to unity.

That is not to imply in any way that the separate traditions have to be abandoned. Within each, reception has been going on. The problem is simply that it has been going on in division. The separated reception-processes with their varied emphases and special insights therefore stand in need of completion by being received by the rest of Christendom. The recognition that there has been separated reception is an acknowledgement that positions stated by only a proportion of the body of the faithful must ultimately be tested by the whole.

In the late 1960s it began to look as though it would be possible to achieve within our lifetimes a definitive coming together in unity between a number of the existing separated communions. After the Second Vatican Council

rapid developments in the doctrinal dialogues initiated at the request of the protestant observers at Vatican II, and encouraged by Pope Paul VI, showed that substantial agreements could be reached in areas that had seemed to be insurmountable barriers … the progress of the bilateral doctrinal dialogues indicated that the Churches of the Reformation and the Roman Catholic Church could be reconciled at least to the extent that the reasons for the original division were resolvable … those involved in the dialogues began to hope that Christian unity might actually be achieved within a generation.

But in many cases the churches which joined in this enterprise so eagerly at first are not proving able to make wholeheartedly their own the agreements arrived at through the dialogues; and consequently they cannot act out such agreements in actually moving towards union. When it comes to turning the (real enough) experience of mutual affection into ecclesial union, everything stops short and the parties tend to retreat towards the familiar ground of their life in division.

Parallels with recent experience in the European Union irresistibly suggest themselves.