The changes that have taken place in religious and ecclesiastical life in Western Europe are characterised as a process of secularisation. Secularisation encompasses three different processes, namely a decline in the religiosity of people, the restriction of the range of influence of religion and the adaptation of religion to the values of society. By means of these processes on three levels the developments with relation to religious life in its entirety can be described. Since changes in religious life are connected with changes in society and the culture of the society in which that religion functions, a better understanding of what secularisation entails demands that we look at those developments in society which have promoted changes in religion and the church. Developments in society that are discussed include the changed organisation of society and processes of rationalisation, democratisation and subjectivation. Finally, it is shown how these developments resulted in the diminishing significance of religion and the churches in and for society.
Since World War II radical changes have taken place in religious and ecclesiastical life in Western Europe and particularly in the Netherlands. To sum up these changes:
- Many church members have become unchurched and the involvement of many of those who stayed behind has diminished.
- For many people the Christian faith has become less important or totally unimportant.
- The Christian religion has also become less important for society as a whole.
- As a result of those developments the position of churches in society has become weaker and more marginal (the separation between church and state is a symptom of this development).
Many people speak about these developments in terms of secularisation. And I think it is correct to say that a fundamental secularisation process is taking place in Western Europe.
But what is the character of this development? What are the causes of it? And, in particular, in which way is this development connected with developments in society as a whole?
We have to have clarity about certain concepts and phenomena (to avoid misunderstandings), particularly the concepts of religion and secularisation.
First, the concept of religion. We have to distinguish between several types of definitions: between evaluative and descriptive definitions and substantial and functional definitions.
Evaluative definitions set out to express what religion is in essence, or what it ought to be. Descriptive definitions set out to describe what it is in day-to-day practice. The choice between these two types of definitions does not present us with great problems: in the sociology of religion -- which wishes to be an empirical discipline -- we use descriptive definitions.
The choice between a substantial and a functional definition is more important. A substantial definition describes religion on the basis of a previously fixed substance or contents; it defines primarily what religion is. A functional definition describes religion on the basis of the functions which it fulfils; it defines primarily what religion does. The difference between the two may be described also as follows: the substantial approach studies a previously defined phenomenon, irrespective of whether that phenomenon is functional in a certain sense or not; the functional approach studies those phenomena which fulfil certain previously defined functions (comfort, meaning, integration), irrespective of whether these phenomena are referred to as religion by the people who are involved themselves or by other people, or not.
An example of a substantial definition (by a sociologist!) is given by Peter Berger, who defines religion as `the human enterprise by which a sacred cosmos is established'.  An example of a functional definition is Yinger's well-known definition: religion is `a system of beliefs and practices by means of which a group of people struggle with the ultimate problems of human life'. 
We choose a substantial definition of religion. Our central question, after all, is what happens to existing religion as a result of changes in society. To answer a question like this, we must start with a phenomenon which has been substantially defined in advance with respect to its contents, and from there we can go on to determine whether the meaning of this phenomenon has altered in the course of time.
We define religion, in the words of Mulder, as an `involvement in some other, decisive reality'. There are two elements which play a role here: `the acceptance of a reality behind or above the visible and tangible empirical reality or, in other words, some other reality which transcends the one we live in'; and man's consciousness that he is `shaped and guided by that other reality in his thoughts, emotions, and behaviour, in a personal sense and as a member of society'. 
In this article we concentrate on the Christian religion, because that is the dominant religion in Western Europe.
In the second place there is the concept of secularisation. There are many opinions about that term and that phenomenon. In common parlance the use of this term is often quite different from scientific usage. But in the scientific world too, even in a single science -- for instance the sociology of religion -- there is no agreement about the meaning of the term secularisation. This is not the place to reproduce these various concepts. But when we speak about secularisation, it is necessary to say as concretely as possible what we mean by the term.
Usually I use the term in three ways; in other words, I distinguish three different processes: 
- Secularisation as the decline of religiosity of people
This is the process in which religious actions and opinions diminish, and/or the significance of these actions and opinions declines in people's lives. This is when the number of church members or their activities in the church decrease, when people pray less or when the significance of prayer decreases, when the relevance of religious conceptions declines, etc.
- Secularisation as the restriction of the range of influence of religion
This is the process by which a growing number of aspects and sectors of individual and collective life become independent of religious influence; religious life becomes more and more restricted to a very small part of life, often referred to as the personal life of the individual.
- Secularisation as the adaptation of religion to society's values
In this process religion adapts itself to developments in society. These are the developments which result in a more secular consciousness and a more secular life of people.
With the help of these three processes (processes on three levels) we can describe developments with relation to religious life in its entirety. For we may say that the first process (secularisation on the individual level) results in a situation in which people secularise; the second process (secularisation on societal level), in which society secularises; and the third process (secularisation on the institutional or organisational level), in which religion secularises.
However, I would like to add two marginal notes. In the first place, the three secularisation processes do not coincide and therefore there is no need for them to take place simultaneously. Because they do not run parallel to each other, this makes it possible to explain a large part of the difference between religious development in the USA and in Europe. In the USA religion has adapted to a great extent to developments in society, with the result that the religious devotion of individual people did not diminish; in fact, it even increased in certain periods. In Europe, on the contrary, religion adapted less, with the result that the gap between religion and modern society became much larger, and religious devotion at individual level diminished greatly. 
In the second place, up to this point we have been speaking about religion and religious activities, but how far does the secularisation process also affect the church? We have to confine ourselves to observing that -- sociologically speaking -- there is a stronger relationship between religion and the church than many believe or want to believe. Therefore, the secularisation process will often affect both religion and the church.
If we look at the developments in religion and the churches, it is beyond doubt that at the moment a fundamental secularisation process is taking place in Western Europe. There is a decrease in religious activity in the populace and a weakening of their relationship with the church. We see, among other things, a decrease in the number of church members (very evident in the Netherlands, but in other countries as well ) and/or a lesser involvement in the church on the whole. Likewise, we see a diminishing significance in religious commitment in the life and activity of the people.
There is also a restriction of the range of influence of religion, as appears from the results of recent research by the European Value Systems Study Group: many people do not have a religious interpretation of everyday reality any more and there is no longer an overall religious meaning system (a `sacred canopy') with a decisive influence on the convictions, values, and norms of the other sectors of life (such as political and economic life).  De-pillarisation in several countries -- especially in the Netherlands (also recently) -- is a symptom of this development.
In the third place, there is the adaptation of religion to its secular environment, as appears from the publications of and the interest in theologians like Robinson, Kushner, and Don Cupitt, as well as from several documents of the churches.
One of the most fundamental suppositions in the sociology of religion is that changes in religious life are directly connected with changes in society and the culture of that society in which that religion functions. For a better understanding of the nature of the secularisation process, we therefore have to look to the development of the Western society and culture. In particular we will look at those developments in society which have promoted changes in religion and the church.
First, there is the changed organisation of society. With regard to this development, sociologists draw attention to the process of social differentiation. In contrast with the past when all kinds of aspects and sectors of life were connected with each other strongly, in modern society these different aspects and sectors have developed and organised themselves more or less independently from each other (for example: family and business). The result of this development is that this is difficult to speak about one (undivided) society. Nowadays we are confronted with a conglomeration of sub-societies, which more or less lead their own lives: the economic world, the medical world, the scientific world, the world of family and friends, etc.
Parallel with this development there is a process of value differentiation. That means that the different worlds not only have their own organisation, but also their own values and value patterns, and that those values develop themselves more or less independently from each other. As a result of this independence there is no longer harmony between the values of the different worlds (there may be a contrast between values in the family and values in business and also between values in economic life and in the medical world).
As a result of the changed organisation of society, people are forced to organise their own lives in another way, too. They do not participate in one society, but they (have to) participate in different subsocieties; they lead -- so to say -- different sublives.
Society as a whole has become very complex and obscure; it has become, in the words of Zijderveld, an `abstract society'.
Modern society is an essentially abstract society which is increasingly unable to provide man with a clear awareness of his identity and a concrete experience of meaning, reality and freedom. This abstract nature of society is caused primarily by its pluralism, i e by its segmentation of its institutional structure.
I define the concept `abstract society' as follows: modern society is, in the experience and consciousness of man, very concrete as to its coercive forces of control, but it evaporates into an awareness of loss of meaning, reality and freedom when modern man tries to keep this coercion under control and to evade the sense of absurdity and inauthenticity. 
The reaction of people to this development is twofold: conformism and privatisation. The individual is `increasingly urged to conform with bureaucratic patterns of behaviour. He has to play the obedient role of functionary and to act according to the demands of invisible authority structures.' At the same time there is the process of privatisation: `In their increasing leisure time, these conformists withdraw into their own private world where they consume the commodities of an affluent society.'  In this way there has arisen not only a distinction, but also a schism between the impersonal and the personal world of people.
Next to the process of differentiation there are some very important cultural processes in our society.
In the first place there is the process of rationalisation. As a result of our greater knowledge there is increasingly the possibility for us to arrange our individual and collective life in accordance with our wishes. And because society is becoming more and more complex, it becomes increasingly necessary that we use our knowledge: that we plan and organise rationally. Consequently, the notion arises that we -- and not an abstract institution or a god -- have to plan, to make, and to rule life, individually and collectively (consider how people speak about birth control, and family planning, and about the self-determination over life and death).
In the second place there is the process of democratisation. Mannheim speaks about the principle of fundamental democratisation . Unlike the previous situation, when most people were dependent on an elite for the organisation of their lives, now basically everybody is responsible for and contributes to the way they lead their lives.
And in the third place we must refer to the process of subjectivation. That is the development by which the (subjective) experience of people becomes more important than so-called objective reality. This process means a change in the form of consciousness of people, with the result that they get another attitude over against values and truths. They interact with them -- as Schelsky says  -- in an ongoing reflection. They become values and truths for them only after they correspond with our experiences.
These processes have a common effect: it is man himself who decides how life will be organised. At the same time, denying or questioning the existence of an objective, fixed regulation of individual or community life that is not made by men, irrespective of whether such a regulation comes from nature, a certain elite or God. With this we have already provided an indication that these processes have radical consequences for the religious life of men.
For, when such important changes take place in the individual and communal life of men, the changes must have consequences for the religious life of men. This is one of the most fundamental presuppositons of the sociologist of religion.
The effect of the process of differentiation is that religious life has also become more and more an own sub-society, an own segment in the whole society. The distinction between religious and non-religious activities and institutions becomes increasingly clear. With a view to this development, Kaufmann  speaks about the Verkirchlichung des Christentums: religion withdraws itself, so to say, from society and shuts itself in the churches. And the churches become separate, and more or less independent segments in society, next to other segments.
As a result of this value differentiation there is a segmentation in value patterns too. The religious values and norms have become more separate from the values and norms in other sectors of society; they are less integrated in society as a whole than formerly. There is not only a privatisation in society in general, but also a privatisation of religion: the faith of people increasingly concentrates on and restricts itself to the personal life of men. The result is that religion and church are no longer situated in the centre of life (symbolised by the church tower in the midst of the buildings), but are shoved away to the margin of life and society.
The differentiation process is one of the most important societal causes of the secularisation process, particularly that process which we call the restriction of the range of influence of religion.
However, other (more cultural) processes in society have great consequences for religious life too.
The increasing rationalisation of our thinking and acting has the effect that more and more people have difficulties with phenomena which are not visible, which one cannot make, cannot rule, and cannot control -- as with everything that does not belong to concrete reality, the reality is manipulatory. It may be clear that this has direct consequences for the existing Christian religion. After all, in this religion people are involved in a reality which is not empirical, or, better, in a God who is `totally different' from people and our empirical reality.
We can say it in another way too: as a result of rationalisation there is a loss of transcendence, and a development towards a more immanent experience and thinking ; and this is at least at odds with the existing (Christian) religion.
[By the way, nowadays -- perhaps also as a reaction to the increasing rationalisation of life -- a great deal of attention is paid to experiences of transcendence too, but often this concerns a very general and vague transcendence; in one of our research reports we spoke about `an empty belief' . But certainly this does not correspond with what is meant by faith experiences in Christian religion.]
Increasing democratisation, particularly the idea that people themselves decide how life and society will be organised, means that many people have trouble with values and truths which are laid down by others or by an establishment. That means that they have difficulties with rules and values which are supposed to come from God, by means of the church and otherwise. The implicit or explicit hierarchic structure of many churches, and the authority of ecclesiastical office holders, is brought into contention, as well as the authority of the Bible, and anything else that does not come from empirical reality (for example, the problem of revelation).
The process of subjectivation has a similar effect on the religious life of people. When our experience becomes normative with regard to values and truths, then it is difficult to accept objective, universal, and fixed values and truths. Objective truth and concentration on our subjective experience are difficult to reconcile. And since the existing Christian religion is characterised, among other things, by objective and eternal truths, the process of subjectivation is a real problem for this religion.
As a result of the effects of the various processes on the individual and communal lives of people, a very great tension comes into being between traditional, ecclesiastically organised religiosity and the experience of life and the modern consciousness of people:
- As a result of the process of democratisation there is a development towards a more human and immanent religiosity, in contrast with the transcendence of the traditional religion.
- As a result of the processes of differentiation there is a development towards a restricted religiosity, in contrast with the Christian faith which is directed at all aspects of life.
- As a result of the processes of privatisation and subjectivation there is a development towards an individual, and with that towards a pluralistic religiosity, in contrast with the common, joint and more or less homogeneous character of the existing Christian religion.
All things considered, the development of our modern society is a real threat to the existing Christian religion. And it is therefore not surprising that a radical secularisation process is taking place in the Western world.
A detailed analysis would bring to light that there are several counter movements too. Here and there we notice a renewed religiosity, and new and alternative religious movements have arisen within the Christian religion (evangelical and charismatic movements) and outside (in Western Europe the Islamic religion in particular). Besides, not all religious groupings have adapted themselves to the developments of society: some have offered strenuous resistance to these developments. But the dominating trend is in the direction of secularisation, by which the restriction of the range of influence of religion -- therefore secularisation at societal level -- is the most important form. 
As a result of these developments, the significance of religion and the churches in and for society has diminished strongly in the course of time.
Traditional religion, even religion in general, has lost its monopoly position in the area of meaning, of world and lifeview. The American sociologist Peter Berger in particular has pointed out this fact.  Religion is located in a market situation nowadays. The Christian religion has to compete with non-Christian religions, and all religions have to compete with non-religious worldviews and value-orientations.
For Western society this is a very important development. The Christian religion has always been, so to say, an ethic religion: that is to say that the Christian world- and lifeviews always formed the basis of norms and rules for the individual and communal lives of men. In this way the Christian religion has been a major element in our society; it functioned as an important foundation of our society and of the values and norms of our society. In other words, the Christian religion functioned as the cement of our society. As a result of the loss of its monopoly position this important function seems to have disappeared.
The significance of the churches has also diminished. Although more and more people leave the churches, this is not the main cause of the diminished influence of the churches (although this is an important factor). The churches still constitute large and important institutions in our society, in which many activities take place.
No, the primary cause of the decreased significance of the churches is the changed character and position of religion:
- In the first place, there is the privatisation of religion: the restriction of the meaning of religion to the personal life of men. The churches accommodate themselves to this development and concentrate on the personal life of people too. This means a weaker relation with and a smaller influence on the public sectors of society.
- In the second place, there is the increased religious plurality in religious life. As a result of this plurality members of the churches are divided on many points. As what they have common is too vague and too abstract to result in a common attitude over against life and society.
- Thirdly, as a result of the loss of their monopoly position, the churches have become more and more dependent on the favour of their (potential) members. This restricts the possibility of the churches developing ideas about society or of influencing society in a way or in a direction which does not correspond with the ideas and the needs of their members.
[One may ask whether the social and political commitment of the churches and the councils of churches after World War II is not in contradiction with what we say about the decreasing influence of the churches. However, on the basis of analysis of the way of acting of the churches we know that this acting has less significance and less effect than it often seems to have.  (I think the situation in South Africa is different from Europe.) No wonder people in the Netherlands think that the churches have less influence in society than many other institutions, for example labour unions, political parties, the mass media, farmers' unions, and even protesters. ]
The conclusion has to be reached that not only the significance of religion, but also the significance and influence of the churches have diminished over time.
Therefore, it is beyond doubt that the secularisation process which takes place is or may be very important for the whole society.
This is less true of secularisation at individual level. After all, it is possible that more people become religious and that people become more active in religious or ecclesiastical matters, but that the significance of religion for society diminishes. This is dependent of the character of the religiosity. For that reason several sociologists are not impressed because people become more religious again (as sometimes is said) or because new religious movements arise. For Wilson these facts are even a confirmation of the process of secularisation, because they demonstrate the irrelevance of religion for modern society. 
Secularisation at institutional level, the adaptation of religion, need not be very important for society either; it may be an inner-ecclesiastical or an inner-religious matter. It is not without significance that Luckmann speaks about `internal secularisation'. 
No, along with the sociologist Weber, we are not concerned with the Wesen der Religion, but with the Bedingungen und Wirkungen einer bestimmten Art von Gemeinschaftshandeln. Therefore, we primarily pay attention to the restriction of the range of influence of religion, thus the secularisation on societal level. And it is clear that in this way institutionalised religion has lost its (formerly supposed) function of all-embracing meaning system.
Several sociologists draw this conclusion.
Luhmann speaks about `functional differentiation' and postulates that people participate in different and separate subsystems, with the result that there is no relationship between, and no mutual influencing of, the different subsystems. Religion belongs to the area of leisure time and therefore is irrelevant to the construction of the society and societal life. 
Luckmann says that the values and norms of the different institutional areas have lost their relationship with the original `superordinated religious values': `what were originally total life values became part-time norms. 
Kaufmann speaks, as we already said, about the Verkirchlichung des Christentums, which results in a secularising of non-ecclesiastical subsocieties or subsystems.
And Wilson postulates:
Religious perception and goals, religiously-induced sensitivities, religious-inspired morality, and religious socialization appear to be of no immediate relevance to the operation of the modern social system. For every social problem, whether of economy, polity, law, education, family relations, or recreation, the solutions proposed are not only non-religious, but solutions that depend on technical expertise and bureaucratic organization. Planning, not revelation; rational order, not inspiration; systematic routine, not charismatic or traditional action, are the imperatives in ever-widening arenas of public life. 
Of course this does not mean that religion cannot be significant for the individual thinking and acting of men. But we are concerned here with its significance for society. And then it seems clear: in our differentiated society, in which people can participate in the different subsocieties only with the help of rather strong role segmentation, and in which religion is privatised very strongly, religion is no longer the constituent factor in European society that it once was (and as perhaps is desirable too). This function has been taken over by other phenomena in society.
To summarise, with the words of the Dutch sociologist Zijderveld, we can say:
Religion no longer binds together the different sectors of life; it has been institutionally isolated into one sector among many, and in the process, it has been relativized into merely one possible explanation of life and the world. This is generally called secularization. In the consciousness of modern man, religion is largely restricted to a particular institutional sector (the Church) where its functions as a kind of private preference on the part of individuals. Recently, forms of religiosity has been emerging outside institutionalized religion ... but they have not as yet penetrated into the larger structures of society. By and large, religion has lost its integrating function with regard to society as a whole. However, industrial society is obviously not an anarchistic chaos. It is apparently still held together in one way or the other. One can then raise the legitimate question as to which force in pluralistic society has taken over from religion its integrative function. Religion has always been the main force of social integration while playing a very strong coercive role. Its substitute in modern society must also exhibit these integrative and coercive features. Taking certain ideas in Weber's discussion of rational organization to their extreme, I propose to view modern bureaucracy as the general coercive force in pluralistic society that keeps this society together as a functionally integrated whole. 
The bureaucracy of society replaced religion. That is secularisation; that is a secularised society.
Peter L Berger, 1967, A sacred canopy, New York, p 26.
J Milton Yinger, 1971, The scientific study of religion, New York, p 7.
D C Mulder, 1971, Het einde van de religie? in Rondom het Woord 13/3 (July), p 294--296.
See also K Dobbelaere, 1981, Secularization: a multi-dimensional concept, London, and M B McGuire, 1981, Religion: the social context, Belmont, p 215--244.
See T Luckmann, 1967, The invisible religion -- the problem of religion in modern society, New York/London, p 28--40.
See for example A Feige, 1976, Kirchenaustritte -- eine soziologische Untersuchung von Ursachen und Bedingungen, Berlin.
See L Halman, 1982, c s, Traditie, secularisatie en individualisering, Tilburg.
A C Zijderveld, 1970, The abstract society, New York, p 53 and 54.
Zijderveld, op cit, p 100.
Karl Mannheim, 1940, Man and society in an age of reconstruction, London, pp 44 ff.
Helmut Schelsky, Ist die Dauerreflektion institutionalisierbar? Zeitschrift fÏr Evangelische Ethik 1 (1957), 4, pp 153--174.
Franz-Xavier Kaufmann, 1979, Kirche begreifen, Freiburg, p 100.
See Peter L Berger, For a world with windows, in Peter L Berger and Richard John Neuhaus (ed), 1976, Against the world for the world, New York, pp 8 ff.
Mady A Thung (et al), 1985, Exploring the new religious consciousness, Amsterdam, pp 116 ff.
This is the form which the British sociologist Wilson always emphasises; see Bryan Wilson, 1966, Religion in secular society.
For instance in The sacred canopy.
See Gerard Dekker, 1977, Gekerkerd geloof, Baarn.
Werkgroep Nationaal Verkiezingsonderzoek 1973, De Nederlandse kiezer `73, Alphen aan de Rijn 1973, p 48.
Bryan Wilson, Contemporary transformations of religion, Oxford 1976, p 76.
Thomas Luckmann, 1967, The invisible religion, New York/London p 37.
Niklas Luhmann, 1977, Funktion der Religion, Frankfurt am Main, pp 232--242.
Luckmann, The invisible religion, p 39.
Bryan Wilson, Religion in sociological perspective, Oxford/New York 1982, pp 176/7.
A C Zijderveld, 1970, The abstract society, New York, pp 145/6.