A lot of words are being thrown about regarding a so-called “return of religion” and the “post-secular” age in which we are now living. Amidst the apparent confusion of the once neatly divided “religious” and “secular” realms, it is crucial to realize the relative novelty of this separation:
The concept of “the secular,” as we use the term today in reference to a domain of social and political life that is decisively non-religious, is relatively new, dating only to the sixteenth century. Prior to the sixteenth century, the term “secular” was still closely related to its meaning within Latin Christendom of “age” (saeculum), and secondarily related to the idea of the present, temporal, mundane world in distinction to the divine and spiritual realm of eternity. This distinction is not equivalent, however, to the distinction between the profane and the sacred, or to our own between the secular and the religious. This inequivalence is due to the fact that, in medieval Christendom, even the saeculum was considered religious. The doctrine of creation meant that everything, including everything in the saeculum, is ultimately related to God (religio); whence Augustine’s characterization of the saeculum as a “mixture” of the earthly city (whose citizens ignore God and love themselves) and the city of God (whose citizens love God first and everything else on that basis). The distinction to make within the Middle Ages, therefore, is not between a purely secular realm and a purely religious realm, but between a mixed secular-religious realm (this world) and a purely religious realm (the other world—heaven), the former subordinated under the latter. (Cauchi, “The Secular to Come,” 3)
This careful historical observation reminds me of the grand, almost mythical, opening of Milbank’s “Theology and Social Theory”: “Once, there was no secular.”