Medieval faith vs reason Part 1

Many medieval philosophers tried to reconcile their belief in a god with the logic and reason of Greek philosophy. In this article, I outline how ten of them tried to do this:

Augustine (354-430), an Algerian Christian.
Boethius (480-524), a Roman Christian.
John Scotus Eriugena (810-877), an Irish Christian.
Psuedo-Dionysius (6th Century), a Syrian Christian.
Al-Farabi / Abunaser (870-950), a Turkish Muslim.
Ibn Sina / Avicenna (980-1037), a Persian Muslim.
Anselm (1033-1109), an Italian Christian.
Ibn Rushd / Averroes (1126-1198), a Spanish Muslim.
Moses Ben Maimon / Maimonides (1135-1204), a Spanish Jew.
Thomas Aquinas (1225-1274), an Italian Christian.

In part two of this article, I will look at how successful they were in their attempts to reconcile faith and reason. First, here is a summary of their efforts:

4th and 5th Centuries: Augustine

Augustine (354-430) was an Algerian who found Platonic and Neoplatonic thinking full of wisdom, but said that he ‘never really fully understood either until he converted to Christianity’. He then sought to incorporate Platonic – indeed, all – human wisdom into this new understanding.
(Martin, 1996: 58, 73).

Like others before him, Augustine adapted Plato’s Good and Forms.

  • The Jewish philosopher Philo (30 BCE-45 CE) had equated them to God and God’s thoughts respectively.
  • The Neoplatonic Plotinus (204-270) had argued that everything emanates from The One to The Nous, or divine intellect.
  • Augustine equated God the Father to The One, and God the Son to The Nous, with Plato’s Forms present to humans through Christ.
  • Plotinus had argued that evil is the absence of good. Augustine adopted this belief to reconcile the existence of God with the presence of evil.
  • Because he saw God as the source of all wisdom, Augustine saw philosophy – ‘love of wisdom’ – as identical to ‘love of God’. He thus devalued the scientific research of Aristotle.

(Stevenson, 2002: 82; Van Fleteren, 1992: 59; Collinson, 1987: 27; Moran, 2003: 9-12)

6th Century: Boethius and Pseudo-Dionysius

Boethius (480-524) was a Roman aristocrat and an orthodox Christian.

  • His Consolation of Philosophy presented Neoplatonic ideas in a Christian context, arguing that this world is a shadow compared to the true, eternal, timeless world.
  • His Latin translation of, and commentary on, Porphyry’s Introduction to Aristotle’s Categories was ‘the book that originally stimulated medieval philosophical debate’.

(Moran, 1993: 9-9; Aubert, 1987: 362).

Psuedo-Dionysius (6th Century) was a Syrian Christian who was later mistakenly identified with Dionysius, a 1st Century convert of Saint Paul.

  • Augustine, influenced by Plotinus, had emphasised ‘the interiority and immediacy of God’s presence in the human mind’.
  • Pseudo-Dionysius was influenced by Proclus – a later Neoplatonist – and he instead proposed ‘a hierarchical universe in which the Divine Light spread downward through a series of intermediate agents to humanity and the lower orders.’

(Dutton, 1992: 175)

9th & 10th Centuries: Eriugena and Al-Farabi (Abunaser)

John Scotus Eriugena (810-877) was an Irish Christian monk who moved to France. He was ‘the most original synthetic thinker between the times of Augustine and Aquinas’ (Dutton, 1992: 170).

Eriugena translated, from Greek, Eastern works of Pseudo-Dionysius and Maximus the Confessor. Maximus had taken the hierarchical emanation of Pseudo-Dionysius, and added the idea that everything is brought together again when the Divine Goodness returns to God.

Eriugena then sought to reconcile this with Augustine’s work. This was the first major attempt to combine Neoplatonic and Christian thought from the East and the West.

Eriugena’s major work is the Peryphyseon, or On the Division of Nature. In this he argues that:

  • Nature is the general name for all things, whether being or nonbeing.
  • There are five modes of interpretation for ‘being-and-nonbeing’.
  • Humans exist in the fifth mode, combining bodies in the material world and Souls in the intelligible.
  • The whole universe is, in this sense, contained in humanity and will return to God.
  • Humans can only know that God is, not what God is.

Eriugena augmented his Neoplatonic influences with a Pythagorean-style mystical discussion of the number eight as a supernatural cube, with the five parts of nature combining with the triad of God on the eighth day-the Resurrection.
(Dutton, 1992: 168-184).

Al-Farabi (870-950), sometimes Latinized as Abunaser, was a Turkish Muslim known as ‘the Second Teacher’ (i.e. second only to Aristotle).

Al-Farabi saw reason and revelation as complementary, and saw philosophers as similar to prophets.

  • Aristotle saw God as the first unmoved mover. Al-Farabi saw God as the cause of the being, as well as the motion, of everything.
  • Aristotle had other unmoved movers, superior to embodied Souls but inferior to God. Al-Farabi saw these as angels.

Al-Farabi then followed a Neoplatonic model: God’s contemplation of Himself overflowed into the existence of a First Intelligence, and thence onward through emanation to all else. His main work, The Virtuous City, was inspired by Plato’s Republic.

(Speake, 1979: 9; Moran, 2003: 9-22; Black, 1992: 115; Feldman, 1987: 408)

10th & 11th Centuries: Ibn Sina (Avicenna) and Anselm

Ibn Sina (980-1037), Latinized as Avicenna, was a Persian Muslim who further developed Al Farabi’s attempts to synthesize all knowledge derived from reason and faith.

  • He drew on Aristotle’s theory of Eudaimonia to argue that the highest aspect of any human being, its intelligence, seeks to reach its perfection.
  • He then drew on Neoplatonism to argue that the way of seeking that perfection is to return to unification with the One from which all emanates – God.

(Gohlman, 1987: 569)

Anselm (1033-1109) was an Italian-born Christian Bishop of Canterbury.

He is best known for his ontological argument for the existence of God: essentially, that ‘that-than which-nothing-greater-can-be-thought’ must exist, because if it did not exist, then it would not be ‘that-than-which-nothing-greater-can-be-thought’.

Whatever the merits of this argument, Anselm thus ‘introduced to the West the idea of proving the existence of God’.

(Lesconcy, 1992: 30)

11th & 12th Centuries: Ibn Rushd (Averroes) and Ben Maimon (Maimonides)

Ibn Rushd (1126-1198), Latinized as Averroes, was a Spanish Islamic Judge who became known as ‘The Commentator’ on the works of Aristotle.

He strongly defended the study of philosophy against theological-legal challenges of heresy under Islamic law.

  • Ibn Rushd argued that not only did the Koran not forbid the study of philosophy, but it demanded it of those capable of doing so.
  • He argued that such study must be built on all previous learning, especially that of the ancient Greeks.
  • Differences with the Koran must be reconciled, as both are forms of truth and ‘truth does not oppose truth, but accords with it and bears witness to it’.

Al-Ghazali (1058-1111) had made influential arguments against Al-Farabi and Ibn Sina in his The Incoherence of the Philosophers. Ibn Rushd responded with his The Incoherence of The Incoherence.

  • Ibn Rushd defended Aristotelian ’cause-and-effect’ against the argument that only God caused any effect, and did so directly.
  • Ibn Rushd responded that denying causality denies not only the existence of essences, but the possibility of knowledge.

Ibn Rushd (Averroes) first seemed to accept the Neoplatonic emanation-of-God theory supported by Al-Farabi and Ibn Sina. Later he rejected it as a metaphor.
(Black, 1992: 68-79; Hourani, 1987: 567)

Moses Ben Maimon (1135-1204), Latinized as Maimonides, was a Spanish Rabbi and the leading intellectual of Medieval Judaism.

His major work, The Guide for the Perplexed, sought to reconcile Aristotelian philosophy with Judaic revelation. He argued that

  • Anthropomorphic descriptions of God in the Bible are metaphorical: ‘The Torah speaks in the language of man’.
  • God can only be described in negative terms: God’s ‘wisdom’ is not the specific presence of wisdom, but the absence of ignorance or defect of knowledge.
  • Spirituality is integrated with reason; reason is the proper means to attain spiritual goals; mystical doctrines do not stand up to reason.
  • Some of the archaic ritual Judaic laws only came about in the context of the struggle between Judaism and paganism in the ancient world.

In seeking to reconcile pagan philosophy with the Torah, he argued that

  • Platonism may seem consistent with the Torah, with prime matter coexisting eternally with God, but it limits God’s power, however slightly.
  • Aristotelian metaphysics are more compatible, to the extent that Aristotle himself at times concluded that the question of the origin of the world is beyond demonstration: it was only later Aristotelians who thought otherwise.

(Wigoder, 1989: 454-455; Dobbs-Weinstein, 1992: 272-273)

13th Century: Aquinas

Thomas Aquinas (1225-1274) was an Italian Christian who sought to reconcile Aristotelianism with Christianity.

Aquinas was particularly impressed with the work of Ibn Rushd (Averroes) in translating and interpreting Aristotle.

Aquinas disagreed with Ibn Rushd’s interpretation of Aristotle’s view of the nature of the human intellect.

  • Ibn Rushd had interpreted Aristotle as saying that intellect is not a faculty of the soul, and there is a single intellect for all humans.
  • Aquinas countered that Aristotle held neither position, and that neither could be rationally defended.
  • Aquinas believed each human has an individual intellect; a position more in line with Christian teaching.

His five Ways of proving the existence of God draw heavily on Aristotle, and to a lesser extent on Plato and Neoplatonism.

  • The first three Ways – Change, Causation and Contingency – rely on causal chains that end at Aristotle’s concept of the first mover.
  • They also rely on a distinction between actual and accidental causes which Aquinas adopted from Ibn Sina (Avicenna).
  • The fourth Way – Gradation – relies on Aristotelian physics and on absolute standards analogous to Plato’s Forms.
  • The fifth Way – Finality – relies on Aristotle’s biological theory that all of nature moves towards a goal.

(Aquinas, De Unitate Intellectus Contra Averroistas;  Aquinas, Summa Theologiae, 1a.2.3; Moran, 2003, Unit 11)

Part Two

In part two of this article, I will look at how successful these medieval philosophers were in their attempts to reconcile faith and reason.


  • Aquinas, Thomas. De Unitate Intellectus Contra Averroistas. In McInerney, Ralph M., 1993. Aquinas Against The Averroeists: On Their Being Only One Intellect. USA: Purdue University Research Foundation.
  • Aquinas, Thomas. Summa Theologiae. In McDermott, Timothy, 1993. Aquinas: Selected Philosophical Writings. London: Oxford World Classics.
  • Aubert, Roger, 1987. Platonism, in The Encyclopedia of Religion. Ed. Mercia Eliade. New York: MacMillan Publishing Company.
  • Black, Deborah, 1992. Al-Farabi; Averroes, both in Dictionary of Literary Biography, Vol. 115: Medieval Philosophers. Ed. Jeremiah Hackett. United States: Gale Research.
  • Collinson, Diane, 1987. Augustine, in Fifty Major Philosophers: A Reference Guide. Kent: Croom Helm.
  • Dobbs-Weinstein, Idit, 1992. Moses Maimonides, in Dictionary of Literary Biography, Vol. 115: Medieval Philosophers. Ed. Jeremiah Hackett. United States: Gale Research.
  • Dutton, Paul Edward, 1992. John Scottus Eriugena, in Dictionary of Literary Biography, Vol. 115: Medieval Philosophers. Ed. Jeremiah Hackett. United States: Gale Research.
  • Feldman, Seymour, 1987. Aristotelianism, in The Encyclopedia of Religion. Ed. Mercia Eliade. New York: MacMillan Publishing Company.
  • Gohlman, William E. 1987. Ibn Sina, in The Encyclopedia of Religion. Ed. Mercia Eliade. New York: MacMillan Publishing Company.
  • Hourani, George F., 1987. Ibn Rushd, in The Encyclopedia of Religion. Ed. Mercia Eliade. New York: MacMillan Publishing Company.
  • Losconcy, Thomas A., 1992. Anselm, in Dictionary of Literary Biography, Vol. 115: Medieval Philosophers. Ed. Jeremiah Hackett. United States: Gale Research.
  • Martin, Christoper J.F., 1996. An Introduction to Medieval Philosphy. Edinburgh University Press.
  • Moran, Dermot, 2003. Medieval Philosophy. In Bachelor of Arts, Philosophy 1. Dublin: Oscail, Dublin City University.
  • Speak, Jennifer (Ed), 1979. A Dictionary of Philosophy. London: Pan Books.
  • Stevenson, 2002. The Complete Idiot’s Guide to Philosophy. Second Edition. Indianaoplis: Alpha Books.
  • Van Fleteren, Frederick, 1992. Augustine, in Dictionary of Literary Biography, Vol. 115: Medieval Philosophers. Ed. Jeremiah Hackett. United States: Gale Research.
  • Wigoder, Geoffrey, 1989. The Encyclodedia of Judaism. Jerusalem, Israel: G.G. The Jerusalem Publishing House.
Image: Part of The Triumph of St thomas Aquinas by Benozzo Gozzoli, 1471
Medieval faith vs reason Part 1

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