During the Congress of Classical Societies at Oxford in August 1948, in discussing the nature and significance of Romanization, I ventured to mention an opinion which had lately found fresh expression about the policy of the Roman government in the early years of its responsibility for the Tres Galliae towards certain features of Gallic life which in ancient times were commonly associated with the Druids. It is an opinion which I myself was once so hasty as to adopt (Universal History of the World—London, n.d.—3, 1998); but when the totalitarians, by setting up a return to barbarism as an ideal, made it the urgent duty of Roman historians to analyse the civilization of Rome and to understand the part played by the Empire in spreading it, the serious examination of the evidence which I ought to have given it before raised very grave doubts about an interpretation which had gained the widespread acceptance of any view commended by the authorityof Mommsen. My reason for raising this matter was its importance; for it is directly relevant to an issue of the most immediate interest—about the nature of the central problem which confronts Europe to-day. And my reason for returning to it now is that it was impossible in an hour's talk, which ranged over a much wider field, to set out the evidence on one particular point in the detail needed to make the position wholly clear— which it is the purpose of this note to do.