How does it feel to know what the truth is when you are everywhere surrounded by doubt? The feeling itself is undoubtedly marvellous to enjoy; it suffuses the body with a glow of certainty, impelling action where others can muster only cynical inactivity. The emotions say: life is worth living; we have a goal, a purpose: we believers are special. But this superabundance of feeling is watched with dismay by the brain. Truth is its preserve after all and it is not so sure: if we are right, then all around are wrong; where are the facts, the data that make us so special, that make sense of and therefore explain and support our joyous certainty? New information keeps pouring into the mind, often threatening to subvert our feelings with fresh ways of describing the world that simply don't fit with our felt knowledge. Is the mind to be our praetorian guard, barring contrary thoughts from entering our emotional consciousness? Or should it in the name of truth join the sceptics and fight raw feeling with disagreeable news from the world of learning?

Jürgen Habermas has remarked of religious beliefs that they require ‘striking cognitive dissonances’ since, as he puts it, ‘the complex life circumstances in modern pluralistic societies are normatively compatible only with a strict universalism in which the same respect is demanded for everybody – be they Catholic, Protestant, Muslim, Jewish, Hindu, or Buddhist, believers or nonbelievers’.