He therefore remained at Hamburg in the capacity of librarian to Johann Friedrich Mayer (1650–1712). In 1696 he accompanied his patron to Sweden; and on his return to Hamburg, not long afterwards, he became a candidate for the chair of logic and philosophy. The suffrages being equally divided between Fabricius and Sebastian Edzardus, one of his opponents, the appointment was decided by lot in favour of Edzardus; but in 1699 Fabricius succeeded Vincent Placcius in the chair of rhetoric and ethics, a post which he held until his death, refusing invitations to Greifswald, Kiel, Giessen, and Wittenberg. He died at Hamburg. The details of the life of Fabricius are to be found in "De Vita et Scriptis J. A. Fabricii Commentarius", by his son-in-law, H. S. Reimarus, the well-known editor of Dio Cassius, published at Hamburg in 1737.