1. One great problem is that the term “secular” is a western term, and corresponds to a very old distinction within Christendom. Then it goes through a series of changes in order to surface in such neologisms as “secularization,” and “secularism.” But even so, some of the original meanings carry over. These terms are then applied unreflectingly to what are seen as analogous processes and ideas elsewhere, and the result can be great confusion. (Example: discussion of Indian “secularism”, whether or not the BJP is “secular”, etc.)
My way of dealing with this has been a prudent (or cowardly) approach of trying to examine the processes we call secularization primarily in the Western context. This however is not a clean and simple solution either, because a) the religious life of other cultures has impacted on the developments in the West (as Peter van der Veer has pointed out), and also one of the facets of contemporary religious life in the West is the borrowing of forms of devotion, meditation and worship from other parts of the world; and b) there has also been borrowing in the other direction, that is by non-Western societies from the West (hence the fact that certain arrangements of the Indian constitution are captured under the cover name “secularism”).
2. If we look at the Western cases first, and try to think of the changes which go under the title “secularization,” we find a very confused set of assumptions and master narratives. The narratives of what were earlier called the “secularization” thesis were often predicated on a) a simple global notion of “religion,” b) a definition of secularity as the absence of “religion”, and c) beliefs to the effect that the inevitable consequence of the changes called “modernization” (economic growth, urbanization, greater geographical and social mobility, the rise of science and technology, the greater importance of instrumental reason, bureaucratic rationality, and so on) was to undermine and marginalize “religion,” and hence bring on “secularization.” (A more recent and sophisticated variant of this narrative can be found in the work of Steve Bruce.)
A more believable form of narrative is rather this: that the developments of “modernity” did indeed, destabilize earlier forms of religious life. No-one could even try to restore the sacral monarchy of France (Indeed, when Charles X tried to restore the full mediaeval coronation ceremony at Reims in 1825—complete with cures for scrofula from the King’s touch—it fell completely flat.) No-one can restore the village parish community whose time is organized around saints’ days and festivals, even though that was still very alive in parts of Europe (not to say Québec) in the first part of the last century.
But this decay of older forms often is followed by a “recomposition” (Danièle Hervieu-Léger’s term) of new forms. Everybody has learned to identify a successive series of forms of congregational Christian life starting with Pietists and Methodists in the 18th Century, and then moving through and into (among others) the Pentacostal movements which in the last 100 years have grown in spectacular fashion (and also have burst well beyond the bounds of the “West”). David Martin has written on this.
3. So a crucial area of work is to recognize the nature and spread of the new forms. New kinds of devotion, discipline, congregational life; but also new ways in which (in some sense) “religious” markers become central to political mobilization, often in competition to more secular” markers (the two models of French nationalism, Catholic versus Jacobin; the struggle in the Arab world between Baathist or Nasserite nationalism and various forms of Islamism); and also the ways in which “religion” is seen as essential to the stability of social-moral order.
In addition, the decline of old and coming of new forms in the West has created a new over-all place of religion or the spiritual in society. Spiritual/religious life is much more self-consciously pluralistic, with ever new forms arising, and with much more scope for individual affinities and conversions.
4. Western “secularization,” properly understood, has involved the displacement of older forms, which saw society as integrated into “Christendom,” and this has a) generated in some cases a bitter struggle to overcome these forms, and marginalize the Churches and modes of faith which sustained them (again the long semi-civil war in France); and b) the resultant pluralism has made some form of public “secularity,” some “neutrality” of the state in face of different spiritual options, or “principled distance” of the state from these, more and more necessary and inescapable.
How this is to be worked out is very difficult to determine, and is the subject of constant disputes. The situation is made worse by an ideology of “secularization” which feeds off the older narrative, which starts from the illusion that “religion” can just be sidelined, e.g., that political debates in a plural society should be carried out in terms of “reason alone” (Kant’s “blosse Vernunft”), without the injection of “religious” premises or arguments; or that we can separate people’s purely secular interests from their religious ones. An outlook of this kind sees any difference arising about the place of religion as the result of an unjust eruption of “religion” into the public sphere, an attempt to set the clock back, etc.
This outlook also nourishes the illusion that there is a simple solution to the problem of religion in society (you just “separate Church and State,” or just adopt laïcité), which can be applied anywhere.