The clash of civilisations is happening not between Islam and the west, as we are often led to believe, but between pragmatic relativism and dogmatic certainty.

What was shocking when Nietzsche first proclaimed it at the end of the 19th century became platitudinous by the start of the 21st.

Some philosophers, such as Bernard Williams and Simon Blackburn, have waded into the public debate in an attempt to put the relativist genie back into the bottle. Books such as Why Truth Matters, by my colleagues Jeremy Stangroom and Ophelia Benson, have also tried to stem the tide.

Truth may not be the simple phenomenon we assume it to be, but falsehoods must be challenged.

those who helped create the impression that modern, secular rationality leaves everything up for grabs in the marketplace of belief will have to take their share of the blame.