Ad fontes is a Latin expression which means "[back] to the sources" (lit. "to the sources").[1] The phrase epitomizes the renewed study of Greek and Latin classics in Renaissance humanism,[2] subsequently extended to Biblical texts. The idea in both cases was that sound knowledge depends on the earliest and most fundamental sources.


The phrase ad fontes occurs in Psalm 42 of the Latin Vulgate:[3]

Quemadmodum desiderat cervus (or Sicut cervus desiderat) ad fontes aquarum ita desiderat anima mea ad te Deus.[4] (As a hart longs for the flowing streams, so longs my soul for thee, O God.)

The phrase in the humanist sense is associated with the poet Petrarch, whose poems Rerum Vulgarium Fragmenta (c.1350) use the deer imagery of the Psalm.[1]

Erasmus of Rotterdam used the phrase in his De ratione studii ac legendi interpretandique auctores:[5]

Sed in primis ad fontes ipsos properandum, id est graecos et antiquos. (Above all, one must hasten to the sources themselves, that is, to the Greeks and ancients.)

For Erasmus, ad fontes meant that to understand Christ in the Gospels in an educated way involved reading good translations of the New Testament, and the Greek and Roman philosophers and Church Fathers in the five hundred years surrounding Christ, over the earlier Old Testament and later Scholastics.[5]

The most extreme version of ad fontes was the Protestant Reformation called for renewed attention to the Bible as the primary source of Christian faith, to the extent of denying extra-biblical apostolic teaching authority: sola scriptura.[6]: 8  This need to select a core that could reject unattractive Catholic doctrines lead to the Protestant rejection of the Deutero-canonical scriptures and queries, e.g. by Luther, on the canonicity or value of the Epistle of James.[7]

Sylvia Wynter is quoted as suggesting that ad fontes heralded a power grab in which the formerly taken-for-granted authority of theology was replaced by “the authority of the lay activity of textual and philological scrutiny.”[8] : 111 

The phrase is related to ab initio, which means "from the beginning". Whereas ab initio implies a flow of thought from first principles to the situation at hand, ad fontes is a retrogression, a movement back towards an origin, which ideally would be clearer or purer than the present situation.

Counter views

Ad fontes may be contrasted with various views of the development of doctrine:

It may be noted that promoters of ad fontes did not necessarily deny the validity of the developments of dogma: notably Erasmus, who saw clarifications of doctrine (by Church Councils and the Pope) as a necessary part of their peace-keeping and uniting role[note 1] that did not negate the wisdom of ad fontes.

See also


  1. ^ He suggested that the Disciples' understanding of the Trinity was relatively undeveloped: "We dare name the Holy Spirit true God, proceeding from the Father and the Son, something the ancients did not dare."


  1. ^ "William Whitaker's Words". Retrieved 11 December 2017.
  2. ^ "The fundamental feature of Renaissance Humanism is summed up in the concept of ad fontes. It was believed that by studying the original texts whether, classical or Biblical, that there could be an actualization of the events described." "The differences between Erasmus and Luther in their aprroach to reform". Justification by faith. Archived from the original on 2007-02-07. Retrieved 2007-02-13.
  3. ^ According to Hans-Georg Gadamer (Truth and Method, p.502 of the 1989 revised English translation) there is evidence provided by E. Lledo that Spanish humanists drew the expression from this source.
  4. ^ Latin Vulgate Bible, Book Of Psalms Psalm 41
  5. ^ a b "On the method of study and reading and interpreting authors." Erasmus von Rotterdam: De ratione studii ac legendi interpretandique auctores, Paris 1511, in: Desiderii Erasmi Roterodami Opera omnia, ed. J. H. Waszink u. a., Amsterdam 1971, Vol. I 2, 79-151.
  6. ^ "Luther and Melanchthon saw theological development as deviation from the purity to be found only and without alteration in Paul, as understood by Luther." Decock, Paul Bernard (16 October 2019). "Erasmus as Reformer: Humanism and Piety—Scholarship and Tolerance". Studia Historiae Ecclesiasticae. 45 (2). doi:10.25159/2412-4265/6735.
  7. ^ Lane, Jason D. (19 January 2016). "Luther's Criticism of James as a Key to his Biblical Hermeneutic". Auslegung und Hermeneutik der Bibel in der Reformationszeit. doi:10.1515/9783110467925-006.
  8. ^ Peeren, Esther (2021). "Suspicious Minds". In Thiele; Kaiser; O'Leary (eds.). The ends of critique: methods, institutions, politics (PDF). Lanham: Rowman & Littlefield. ISBN 9781786616463.
  9. ^ Chesterton, Gilbert Keith (1933). St. Thomas Aquinas.
  10. ^ Newman, John Henry (1909). An Essay on the Development of Christian Doctrine, by John Henry Cardinal Newman (14th impression ed.). London: Longmans, Green, and Co. Retrieved 16 December 2023.
  11. ^ Rummel, Erika (1992). "Et cum theologo bella poeta gerit: The Conflict between Humanists and Scholastics Revisited". The Sixteenth Century Journal. 23 (4): 713–726. doi:10.2307/2541729. ISSN 0361-0160.

Further reading