The cases of over 2.000 potential saints are now under the consideration of the Vatican in Rome. Whether they become examples of 'heroic virtue' to set before the faithful, or sink into obscurity, depends largely on the strength of the claims made by their supporters. The scales, however, can be tipped either way by less predictable factors. Libby Purves considers the painstaking inquiry that assesses sanctity and can turn heroes into saints.

BBC North West