I did not choose the questioning title of this exchange, and nor I presume did Lawrence Krauss, but it was given to us as a starting point to consider issues of secularism and religion. Let me begin, then, by clearing the ground by drawing and commenting on a couple of distinctions: first, that between secularisation and secularism, and second that between the non-establishment of religion and religion-state separation.
The former is a distinction between an explanatory-predictive theory and a normative view: secularisation holds that as a society becomes more scientifically and technologically sophisticated so it becomes less religious, secularism holds that religion has no place in the organized and specifically political life of a society. The latter distinction relates to secularism but is more specific holding either (non-establishment) that while religion may have a place in the life of society no particular religion nor non-religion should be politically privileged, or more extensively (separation) that religion as such and in all its forms ought to be kept entirely distinct from the organized life of society. As is the usual way, weaker or stronger, and less and more specific versions of these views may be advanced.
Just to complete this introductory phase let me conjecture that Lawrence Krauss’s opinion is that some version of secularisation is true and that secularism should be favoured in the stronger version represented by separation. By contrast, my view is that as a general thesis secularisation is false, and that while non-establishment is reasonable, separation is not.
‘Society’s ills’ is a broad and vague notion, but while I believe that forms of religion can be special sources of good, I do not believe that religion per se (whatever that could be) is a protection against or remedy for social evils. Indeed a religion, just like a political or philosophical ideology may be an agent or vehicle of these (as, for example, when idolatrous, misanthropic, narcissistic, oppressive or totalitarian). On the other hand, I think there are some evils that only certain forms of religion can explain and offer remedies for.
Krauss writes that “secularism … has as its basis the claim, now validated by over 400 years of scientific progress, that there is no need for supernatural postulates in order to understand both the workings of the Universe and the affairs of humankind.” If “the workings” means natural processes and “understand” means explain scientifically, then this is truistic and close to tautological; but that begs the question whether those workings presume conditions (such as there being anything at all, and what there is exhibiting order) that they do not, and ex hypothesi, cannot themselves explain; for the presuppositions of the possibility of science are not themselves open to scientific enquiry.
More to the present point, however, is the matter of the ‘affairs of human kind’. Various material and social sciences are relevant to the explanation of aspects of human experience and behaviour, but what of questions of value and meaning? ‘What could we do? is a technological question, ‘what would we do?’ is a socio-psychological one; ‘what should we do?’ is neither: it is an evaluative one. Again, what explains the physical properties of a painting or of a piece of music are broadly scientific questions but what the meaning or aesthetic value of an artwork is are not amenable to scientific explanation.
Turning to specifically religious rather than more broadly evaluative matters, and to the accounting and resolution of them, it is common enough for thoughtful, reflective people to recognise their propensity to existential anxiety, self-deception, weakness of will and emotional disorder. Further reflection indicates that these are not merely individual or occasional failings, but more akin to species pathologies exhibited as causes and cases of personal and social ills across the range and history of human societies.
One serious explanation of these is that they are not natural but spiritual conditions due to spiritual causes and requiring spiritual remedies. The term ‘supernatural postulates’ is relevant here because in its original and still proper use ‘supernatural’ is a theological term meaning not merely non-natural, as might ‘spooky’ or ‘magical’ or ‘preternatural’, but relating to God and the gift of grace in countering the effects of sin and nourishing the soul. Of course, one may choose to set aside religious ideas in explaining ‘the affairs of humankind’ but without serious argument that is again to beg the question. And if some form of religion has a credible explanation of, and postulated source of remedy for those ills then it would be unreasonable and inhumane to insist, as secularism does, that it be kept entirely distinct from the organized life of society.