Despite the theological and popularly conceived connections between religious devotion and moral living, the difficulties attending theological or religious ethics — the attempt to tie ethics to theology or religion in some important sense — are myriad. Thanks largely to Enlightenment thought, morality has come to be construed as independent of God so much so that the majority of moral philosophers today would without without hesitation affirm that even if God exists, morality can exist apart from God — an ontological critique — and, if the precepts or dictates of morality can be known at all, they can be known apart from religious orthodoxy or theological reflection — an epistemological critique. ¶ Since the Enlightenment, at least, and in particular since Kant’s epistemological dualism, questions of religion and “speculative metaphysics” have often been considered beyond the ken of rationality. Kant’s motivation, it has been suggested, was to spare religion from the rigorous scrutiny of the emerging science of his day; but the actual result proved to be detrimental to religious conviction, for it began to be portrayed as an inescapably subjective affair. Universal truth claims became harder to reconcile with this kind of epistemology, which is likely the inevitable while paradoxical effect of implicitly putting religion and science at odds. Religious truth claims tend to be increasingly construed as devoid of propositional content and rational evidence and are instead seen as empty faith claims rooted in a person’s imagination or a group’s collective psyche.

Nonetheless the mistakenly perceived tension between science and religion contributed to their artificial separation. It was long thought that morality could be salvaged from such a fate by being rooted in reason rather than revelation Indeed, this effort serves as one effective summary of the Enlightenment: to sound ethics in reason rather than religion and thereby retain its authoritative force. however, severed from its ontological foundations, morality has provided notoriously difficult to undergird by reason alone, so much so that the Enlightenment project has recently often been characterized as a failure. One result is that morality, still often perceived to be in religion’s vicinity, is increasingly absorbed into Kant’s nominal realm of the unknowable, inscrutable and, for practical purposed thereby construed as a purely individual affair. This despite the obvious fact that Kant himself was no subjectivist in ethics.