Barth argues that 18th-century rational theology was rooted in prior commitments to peaceable citizenship and morality. The dynamic goes something like this: Christianity is interpreted pragmatically – it’s about the transformation of human life; but it doesn’t work – human life isn’t transformed; there must therefore be something wrong with Christianity itself. All the scientific and philosophical discoveries of the 18th century are picked up as tools to critique a Christianity that doesn’t mean prior moralistic standards.
Generalizing, Barth adds “Psychologically speaking, abstract theories of Christianity, whether they are positive or critical, are always a compensation for an actual (albeit at times very hidden) deficiency in Christian practice.”
