The problem of the neutrality of Delos has been the subject of a searching investigation by W. W. Tarn published recently in this Journal. The argument turns mainly on a purely epigraphical question, namely, the interpretation of the formula for the setting-up of a stele in the decrees of the Island League. Its historical importance is great, because, if Tarn is right, we should be justified in utilising the Delian Royal festivals for the reconstruction of the political history of the third century, which has rightly been styled the darkest period of Hellenism. As in the fourth Excursus of his large work Antigonus Gonatas, the distinguished scholar maintains the thesis that Delos became a member of the Island League, and that the varying history of this League is reflected in the establishment of festivals in turn by the Ptolemies, by the Seleucids, and by the Antigonids. The evidence for his theory he finds in the argument that the Islanders, if they wished to set up an inscribed stele in Delos, were not obliged to address a petition to the Commune of Delos, requesting the grant of a site in the sanctuary; the Islanders therefore controlled the site and ground of Delos, which implies that Delos belonged to the League. Although I raised objections to Tarn's thesis, as did Roussel at an earlier date, I would gladly be the first to agree with him, had he succeeded in bringing forward convincing proof of this theory. As this has not been the case, in view of the wide significance of the problem I think it advisable to break silence and to expose my objections to the criticism of experts.