Friedrich von Hügel (1852-1925), an autodidact whose main field of competence was that of Biblical studies, was a prominent figure in the modernist crisis. Amongst the vast network of relations, at the same time scholarly and friendly, which he maintained with numerous scholars of his day, were Bollandists, in particular Hippolyte Delehaye. The letters exchanged between von Hügel and Delehaye throw light upon the methods and demands of modern criticism. They also bear eloquent witness to the interference and vexations by which learned Catholics were confronted when they applied these methods. — As for the correspondence between Delehaye and Cuthbert H. Turner (1860-1930), an Anglican, exegete and historian of the early centuries of Christianity, it provides a touching example of the relations between two scholars of different confessions who carried out their research with the greatest of rigour but each with respect for the conscience of the other.