Was nineteenth-century philosophy merely a substitute for religion? The American philosopher Richard Rorty once argued precisely that. Rorty saw intellectuals of the long nineteenth-century (c 1789-1914) as being preoccupied by secular concerns: and at first his assertion does seem plausible. From Immanuel Kant and G W F Hegel to F H Bradley and Charles Peirce, philosophers of the period attempted to discuss knowledge, morality, freedom and ethics on terms that made no appeal to any special revelation or divinity beyond reason. But this lively survey argues otherwise: that Rorty’s claim is not only an over-simplification, but wrong. The ideas of the leading nineteenth-century thinkers were not mere substitutions for religion: they were motivated by deep religious concerns. Søren Kierkegaard famously grappled with God, truth and doubt even as he lambasted the Danish church. If Nietzsche is the notable exception then he proves the rule since, as he remarked himself, one saw ‘the theologian instinct’ everywhere in the spirit of his age. Joel Rasmussen deftly charts the key discussions of an era when the problem of God refused to die.