Tychonius a Donatist of the 4th century, who displayed an impartial and sincere desire to arrive at the truth with respect to the controversy between his sect and the Church. He is described as having been learned in the Scriptures, tolerably acquainted with history and with secular literature, and zealously interested in the affairs of the Church. He regarded the Church as the sole divinely provided remedial institution, into which all men must enter if they would attain to salvation; and therefore held that the moral state of the members cannot destroy the value and efficiency of the Church. He was also consistent in protesting against the rebaptism of persons who became Donatists. His views were attacked as heretical by the Donatist Parmenian (q.v.), and drew forth an epistle from Augustine. Tychonius was accused of being a Chiliast, but the charge is probably untrue. A single work from his pen remains, the Liber Septen Regulis, first published by Grynmeus (Basle, 1569), and afterwards in a better edition by Gallandi in the Bibl. Vet. Patrum (Venet. 1772), 8:107-129. The work is designed to serve as a guide to the interpretation of the Scriptures, and some of its rules are still followed by some expositors e.g., the sixth, De Recapitulatione, which teaches that the same thing is sometimes repeatedly narrated or described, especially in the Apocalypse, so that successive narratives do not necessarily refer to successive events. The book furnished Isidore of Seville the idea for his work Sententiarum Libri Tres. As the earliest endeavor to construct a theory of Christian hermeneutics, the work certainly deserves attention. It would appear from Augustine that Tychonius died about 390; but Gennadius (De Script. Eccles. c. 18) fixes a later time. Gallandi furnished a sketch of Tychonius in Proleg. to Bibl. Vet. Patr. VIII, 2, 5, and a more careful notice is given in Tillemont, Memoires pour servir a Hist. Eccl. des Six premiers Siecles (2nd ed. Paris, 1704), 6:81 sq., 145- 150. See Herzog, Real-Encyklop. s.v.