Laudator Temporis Acti

Kenneth Jackson (1909-1991), "Fifty Years of Celtic Philology," Modern Language Review 71.4 (October, 1976) xxiii-xxxvii (at xxiii-xxiv):

Celtic studies are peculiarly dangerous for the amateur, but there has recently been an unfortunate tendency for scholars, even good scholars, in other fields such as the history of Roman Britain, post-Roman archaeology and history, or in the study of English place-names, to venture rashly into the Celtic field where they are not qualified to do so. This is apparently on the principle that 'After all, no one knows anything about Celtic anyway, so why shouldn't I have a stab?'. Unluckily for them, some people do know something about Celtic. The result has too often been that where Celtic seems to impinge on their own subject, the writers just mentioned dream up and publish ideas which the Celticist knows to be absurd speculations, which nevertheless tend to be taken for fact when a sufficient number of other unqualified persons have repeated them as such in print, so that eventually they become unchallengeable dogma.