Science and Faith issues in Ancient and Medieval Christianity, Part 2

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The flat earth in Ancient Christianity

The School of Antioch arose as a reaction to perceived excesses in the allegorical interpretation of Scripture as practiced by the School of Alexandria. Eustathius, the 4thcentury bishop and patriarch of Antioch, wrote the radical and groundbreaking early treatiseOn the Witch of Endor and Against Allegory highlighting inconsistency in Origen’s allegorical interpretations and emphasizing the importance of contextual readings for maintaining consistency and faithfulness in interpretation. Antiochene scholars argued that a text could not say more than could be connected to its literal and historical context. The leading teachers included Diodore of Tarsus and two of his students: the exegete and commentator Theodore of Mopsuestia and the great expository preacher John Chrysostom. The School of Antioch is known more for its influence on the development of Nestorianism, a Christology that advocates two natures in Christ, a divine and a human. But its influence is seen in its development of biblical reflections on the natural world. Chrysostom displays such a literal reading in his discussion of the earth being carried on waters:

Whence does this appear, that the earth is borne upon the waters? The prophet declares this when he says: ‘He founded it upon the seas and prepared it on the floods’, and again, ‘To him who founded the earth upon the waters’ What do you say?[1]

This hermeneutic, when pressed consistently, leads to a cosmology that includes a flat earth. The Homilies on Creation and Fall (circa 400 A.D.[2]) by Severian of Gabala, a Syrian bishop who moved to Constantinople in the early 5th century and became closely associated with John Chrysostom (to the extent that his writings were transmitted under the name of Chrysostom for many centuries), exemplify a group of Antiochian interpreters who read the biblical text as teaching that God created heaven and earth in the shape of the tabernacle and who therefore were compelled to reject and attack belief in a spherical cosmos. For example, Severian writes against those who believe in a spherical world:

He did not create heaven as a sphere, as the idle talkers claim; he did not make it as a sphere moving on its axle. Rather, as the prophet asks, what course does the sun follow? ‘He arches the heaven like a curved roof and extends it like a tent’ [Isaiah 40:22]. None of us is so impious as to be convinced by the idle talkers. The biblical authors say that the heaven has a beginning and an end; hence the sun does not climb—it travels. Scripture says, ‘The sun had emerged upon the earth when Lot entered Zoar’ [Genesis 19:23]; so it is obvious that the sun emerged, as Scripture says, and did not climb. And again, ‘from the furthest point of heaven was its emergence’ [Psalm 19:6], not its ascent: if it were a sphere, it would not have a furthest point; what is the furthest point of something completely circular? Surely it is not only David who says this, therefore, or even the Savior? Listen to his words [Matthew 24:31]: ‘When the Son of man comes in his glory, he will send his angels with a loud trumpet call, and they will gather his elect from one end of heaven to the next.’[3]

Going even further, Cosmas Indicopleustes (whose true name was Constantine of Antiochia[4]) exemplifies in the 6th century the fiercely polemical and apologetic approach against the Hellenistic ‘pagan’ science that was mainly associated with Alexandria. Cosmas extracted as much science as possible from these very same verses to defend a box-like ‘biblical’ cosmology with a flat-earth at the bottom in his Christian Topography.

This is the first heaven, shaped like a vaulted chamber, which was created on the first day along with the earth, and of it Isaiah speaks thus: He that hath established the heaven as a vaulted chamber. But the heaven, which is bound to the first at the middle, is that which was created on the second day, to which Isaiah refers when he says: And having stretched it out as a tent to dwell in. David also says concerning it:Stretching out the heaven as a curtain, and indicating it still more clearly he says: Who layeth the beams of his chambers in the waters. Now, when Scripture speaks of the extremities of heaven and earth, this cannot be understood as applicable to a sphere. […].[5]

[…] we have exhibited the Christian theories concerning the figure and position of the whole world from divine scripture; […].[6]

Cosmas found support in Eccl. 1:6 for his view that the sun circles a huge mountain in the north, thereby producing the night when it is behind it:

[…] according to the wise Solomon, […] The sun ariseth and goeth towards the south and moveth round to the north; the wind whirleth about continually and returneth again according to its circuits.[7]

Cosmas directed vitriolic attacks against Christians who accepted the Hellenistic science and, particularly, the sphericity of the earth, which he considered the major mistake of that scientific worldview.

[…] some supposed to be Christians, holding divine scripture of no account but despising and looking down upon it, assume like the Pagan philosophers, that the form of the heavens is spherical, being led into this error by the solar and lunar eclipses.[8]

Were one to call such men double-faced he would not be wrong, for, look you, they wish both to be with us and with those that are against us, thus making void their renunciation of Satan whom they renounced in baptism, and again running back to him.[9]

[…] those miserable men admit the spherical form of the heaven to be true, disbelieving, yea, rather execrating, the whole of divine scripture […].[10]

Interestingly, these attacks were rejected in his own time by Philoponus of Alexandria, the 6th century Christian philosopher and scientist who represented all that Cosmas hated. Philoponus never mentioned Cosmas directly; instead he criticized the top representatives of the Antiochian school (particularly Theodore by name and, indirectly, the ideas from Severian that Cosmas quoted). Philoponus denied that the Bible was a book of science, being instead a path to reach the knowledge of God. He considered himself a follower of Basil on the theological side of the debate, and a defender of the Ancient Hellenistic science on the scientific issue of the shape of the earth and other astronomical knowledge (stating clearly his rejection to astrology). This was a difficult position to hold, and at times he fell into the complexities and inconsistencies of science-Bible concordism, like Basil, as he tried to fit Genesis 1 with Hellenistic science to avoid the conflict. However, he was admirable in his commitment to defend both Christianity and science in his commentary on Genesis, and rebuttal of Cosmas, De Opificio Mundi. Philoponus devoted the third book of this seven book treatise to attack the Nestorian Antiochian school, using Hellenistic science as well as sophisticated biblical hermeneutics, frequently influenced by Basil, to respond to their many arguments, not being afraid to counter-attack with strong language.

If certain people, owing to the uneducated state of their soul, cannot attain to what has been said and are troubled about the way the facts are put together, silence will help them to cover up their own ignorance. And let them not tell lies about God’s creation out of their own lack of experience and the slowness of their mind, fearing the retributions for a lie. […]. What punishment do they deserve who lie about such works of God? Let them hear it from him: “My name is blasphemed by you everywhere among the nations.”

For those who grasp investigations of matters of the heavens with accuracy and witness in their words that they possess perception both about the other things I have already said and about eclipses of the sun and moon, […].[11]

[…]. Thereby it is again patently demonstrated that as much of the heaven as is above the earth, so much again of it is below the earth, being one single sphere complete out of two hemispheres. […].[12]

Some people’s saying that it [the sun] is carried by the north winds to return to the east, being hidden by very high mountains, was an ancient and foolish notion held by some which deserves the laughter befitting it, […].[13]

Interestingly, and contrary to the impression commonly left after the rediscovery of Cosmas in the early 18thcentury, his work was not the beginning or even the pinnacle of flat-earth cosmological influence among Christians. It was rather the opposite; this most elaborate defense of the flat earth seems to have brought the discussion to its end. As far as we can track in the extant Christian texts of late Antiquity and the early Medieval period, there seem to be no followers of Cosmas.

The two known direct references to Cosmas in Eastern Christianity were critical (Shirakatsi, 7th century, Armenian scientist) and very negative and even sarcastic (Photius, 9th century, Patriarch of Constantinople: “he [Cosmas] may fairly be regarded as a fabulist rather than a trustworthy authority.”[14]) Additional criticisms were directed at the flat earth beliefs of Diodore of Tarsus. Consideration of other contemporary authors addressing topics of cosmology suggest Cosmas carried no weight since these writers ignore him and show no interest in his ideas. Instead there is a continuation of the Ancient Hellenistic cosmologies.

Likewise, the situation in Western Christianity was not favorable to Cosmas’ views. We know from Augustine (4th-5th centuries, Bishop of Hippo) that debates on the shape of the earth existed at the time, and in the early 4thcentury, the Christian writer Lactantius attacked with vigor the sphericity of the earth in connection with his aggressive denial of the antipodeans (see below).

Augustine himself was never very clear on the topic and, indeed, there has been a discussion up to our present time on whether Augustine himself was a flat-earther, sphericist, unsure, or just did not want to commit himself. In any case, it is very clear that he was not a defender of the flat earth in the way Cosmas or even Lactantius (whose work Augustine knew and used in other contexts) were. In general, we can say that Augustine followed a line of thinking going back to Ambrose in the West and Basil in the East that highlighted the irrelevance of the cosmological speculations for the spiritual life of a Christian, and therefore was prone to show a non-committal position on these topics. Of course, this position was sometimes a disingenuous position, crafted to avoid the pagan attacks on the Bible as supporting antiquated cosmological ideas. Retreat was a better strategy than fighting on topics where a victory was seen as unsure, a far cry from the naïve and dangerous attacks from Cosmas and Lactantius to Hellenistic science.

Another author of great influence in the West was Isidore (6th-7th centuries, Archbishop of Seville). As with Augustine, there has been an ongoing debate up to our time on whether he was a flat-earther. Although his work contains some ambiguous passages, we cannot find any clear defense of a flat earth cosmology or attacks to the sphericity of the earth. In addition, his disciple, the Visigothic king Sisebutus (6th-7th centuries) composed an astronomical poem where he explained the eclipses in the traditional sphericist fashion. Finally, the English monk Bede (7th-8th centuries) explained very clearly the sphericity of the earth in his scientific work, which became one of the most important influences in the West during the early Medieval period.

  1. Homilies on the Statutes 9:7 W. R. W. Stephens’ translation in Schaff’s NPNF 1.9. [return to body text]
  2. R. E. Carter. ‘The Chronology of Twenty Homilies of Severian of Gabala’. Traditio 55 (2000):1-17. [return to body text]
  3. Translation by R. C. Hill in Commentaries on Genesis 1-3. Severian of Gabala and Bede the Venerable. Ancient Christian Texts. Series edited by T. C. Oden and G. L. Bray. Downers Grove: Inter-Varsity Press, 2010. Text from Homily Three, page 44. [return to body text]
  4. W. Wolska-Conus. ‘Stéphanos d’Athènes et Stéphanos d’Alexandrie. Essai d’identification et de biographie’. Revue des etudes Byzantines 47 (1989):5-89. [return to body text]
  5. Cosmas Indicopleustes. The Christian Topography IV. Tr. J.W. McCrindle. London: Hakluyt Society, 1897, page 130. [return to body text]
  6. Idem, VII, page 265. [return to body text]
  7. Idem, V, page 152. [return to body text]
  8. Idem, Prologue II, page 4. [return to body text]
  9. Idem, V, page 10. [return to body text]
  10. Idem, III, page 128. [return to body text]
  11. Philoponus. De Opificio Mundi III.8. Tr. L. S. B. MacCoull (unpublished, 1995, kindly provided by the translator), page 106. [return to body text]
  12. Idem, III.9, page 111. [return to body text]
  13. Idem, III.10, page 117. [return to body text]
  14. Bibliotheca 36 [return to body text]




Keay, Robert D.. "Science and Faith issues in Ancient and Medieval Christianity, Part 2" N.p., 3 Dec. 2013. Web. 13 December 2017.


Keay, R. (2013, December 3). Science and Faith issues in Ancient and Medieval Christianity, Part 2
Retrieved December 13, 2017, from /blogs/archive/science-and-faith-issues-in-ancient-and-medieval-christianity-part-2

About the Authors

Pablo de Felipe

Pablo de Felipe obtained a PhD in Chemistry (Molecular Biology) at the Universidad Autónoma de Madrid (Spain). He worked as a Research Fellow at the University of St Andrews (Scotland) before joining the Spanish Medicines Agency. Since April 2016 he is a lecturer in science and faith at the SEUT School of Theology, and Evangelical institution in Madrid, Spain ( where he also coordinates the Centro de Ciencia y Fe (Centre for Science & Faith,, belonging to the Fundación Federico Fliedner (

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Robert D. Keay

  Robert Keay earned the PhD in New Testament at the University of St Andrews (Scotland), where he also served as a Teaching Fellow in New Testament. He then moved to Northern Ireland where he taught for several years as a Lecturer in New Testament and Hellenistic Greek at Queen's University, Belfast (N. Ireland). He has recently entered the ministry as Pastor of First Baptist Church, Wolfeboro, New Hampshire.

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