But if we are prudent (or perhaps cowardly), and reflect that we are trying to understand a set of forms and changes which have arisen in one particular civilization, that of the modern West — or in an earlier incarnation, Latin Christendom — we see to our relief that we don't need to forge a definition which covers everything "religious" in all human societies in all ages. The change which mattered to people in our (North Atlantic, or "Western") civilization, and still matters today, concerning the status of religion in the three dimensions of secularity I identified, is the one I have already started to explore in one of its central facets: we have moved from a world in which the place of fullness was understood as unproblematically outside of or "beyond" human life, to a conflicted age in which this construal is challenged by others which place it (in a wide range of different ways) "within" human life. This is what a lot of the important fights have been about more recently (as against an earlier time when people fought to the death over different readings of the Christian construal).
In other words, a reading of "religion" in terms of the distinction transcendent/immanent is going to serve our purposes here. This is the beauty of the prudent (or cowardly) move I'm proposing here. It is far from being the case that religion in general can be defined in terms of this distinction. One could even argue that marking our particular hard-and-fast distinction here is something which we (Westerners, Latin Christians) alone have done, be it to our intellectual glory or stultification (some of each, I will argue later). You couldn't foist this on Plato, for instance, not because you can't distinguish the Ideas from the things in the flux which "copy" them, but precisely because these changing realities can only be understood through the Ideas. The great invention of the West was that of an immanent order in Nature, whose working could be systematically understood and explained on its own terms, leaving open the question whether this whole order had a deeper significance, and whether, if it did, we should infer a transcendent Creator beyond it. This notion of the "immanent" involved denying — or at least isolating [16] and problematizing — any form of interpenetration between the things of Nature, on one hand, and "the supernatural" on the other, be this understood in terms of the one transcendent God, or of Gods or spirits, or magic forces, or whatever. 17
So defining religion in terms of the distinction immanent/transcendent is a move tailor-made for our culture. This may be seen as parochial, incestuous, navel-gazing, but I would argue that this is a wise move, since we are trying to understand changes in a culture for which this distinction has become foundational.
So instead of asking whether the source of fullness is seen/lived as within or without, as we did in the above discussion, we could ask whether people recognize something beyond or transcendent to their lives. This is the way the matter is usually put, and I want to adopt it in what follows. I will offer a somewhat fuller account of what I mean by this distinction several chapters down the road, when we come to examine modern theories of secularization. I fully recognize that a word like "transcendent" is very slippery — partly because, as I hinted just now, these distinctions have been constructed or redefined in the very process of modernity and secularization. But I believe that in all its vagueness, it can serve in our context.