Not everyone tells the truth. ‘Read my lips: no new taxes.’ ‘This isn’t going to hurt.’ ‘I see no ships, my lord.’ ‘Of course I love you.’ When can we know what to believe Four out of five of us don’t think politicians tell the truth, according to a recent MORI poll. But is telling the truth always the right or best thing to do If it isn’t, what happens to trust If it is, are there different kinds of truth Do we always want to hear the truth Do different professions need to have systemically different attitudes to truth-telling Is there a moral difference between outright lies, falsehoods, deceits, dissimulation and just plain old ‘economy with the actualité’In October 1013, Intelligence Squared headed to London's Westminster Abbey to discuss truth with a politician (Jack Straw), a journalist (Max Hastings), a scientist (Professor Robert Winston) and a poet (Wendy Cope).