heretic. A native of Britain, he was practising as an advocate in Rome when he met Pelagius. They became convinced that the contemporary low morality could be reformed only by stressing people's responsibility for their actions, and so began teaching a doctrine of free will that left no room for grace. Celestius denied that Adam's sin was transmitted to his descendants (Original Sin). He migrated to Africa c.410, was condemned by the 411 Council of Carthage, and went to Ephesus. See also Pelagianism.