What medieval philosophy is
Medieval means 'of the Middle Ages', the period between the ancient world and the modern world (about 400–1450 CE). Philosophers then lived in Christian, Islamic and Jewish societies, so religion was central. Their main question was: how do faith and reason fit together?
- Faith: trusting truths that are revealed (in holy books and teaching).
- Reason: working things out by careful thinking and evidence.
They also asked: what is real? How do we know things? What is a good life? Is the will free? Many of their ideas came from ancient Greek thinkers, especially Plato and Aristotle.
Augustine and the Church Fathers (Patristics)
The early Christian writers are called the Church Fathers; their thought is patristics. The most important is Augustine of Hippo (354–430), from North Africa.
- Look inward: truth is found by turning into the mind, where God gives an 'inner light' (illumination).
- Faith seeks understanding: believe first, then use reason to understand more deeply.
- Doubt answered: 'If I am mistaken, I exist', so some knowledge is certain.
- Evil is not a thing but a lack of good; it comes from the misuse of free will.
- Time lives in the mind as memory (past), attention (present) and expectation (future).
- The two cities: the city of God (love of God) and the earthly city (love of self).
Augustine was strongly influenced by Plato's idea of a higher, unchanging world.
Keeping and passing on knowledge: Boethius and Islamic and Jewish philosophers
Boethius (c. 477–524) translated parts of Aristotle's logic into Latin. In prison he wrote The Consolation of Philosophy: luck can take away wealth and fame, but not true happiness, which lies in the good.
Much of Aristotle was then lost in Western Europe but studied in the Islamic world:
- Al-Kindi and Al-Farabi joined Greek thought with Islamic learning.
- Avicenna (Ibn Sina, 980–1037): separated a thing's essence (what it is) from its existence (that it is). His 'floating man' test: a person floating in air, with no senses, would still know they exist.
- Averroes (Ibn Rushd, 1126–1198): 'the Commentator' on Aristotle; true reason and true religion cannot contradict each other.
- Maimonides (1138–1204): Jewish thinker who read scripture in harmony with reason.
In the 1100s scholars in places like Toledo translated these works into Latin, and Aristotle returned to Europe's schools.
Scholasticism: the method of the universities
Scholasticism ('of the schools') was the way of teaching in the new universities such as Bologna, Paris and Oxford (from about 1100). It used logic to test every question:
- State the question.
- List the objections (the best arguments for the other side).
- Give the answer with reasons and authorities.
- Reply to each objection.
Anselm of Canterbury (1033–1109) is called the father of scholasticism. His motto was 'faith seeking understanding'. His ontological argument: God is 'that than which nothing greater can be thought'; a being that exists in reality is greater than one only in the mind; so God must exist in reality. The monk Gaunilo objected: by this logic we could prove a perfect island exists.
Another big debate was the problem of universals: is 'redness' or 'humanity' a real thing, or only a name we give to similar things?
Thomas Aquinas: faith and reason as partners
Thomas Aquinas (1225–1274), an Italian friar, joined Aristotle's philosophy with Christian teaching in his great book, the Summa Theologiae.
Faith and reason
Some truths can be known by reason alone (that God exists, basic morality). Others need faith (revealed teachings). Both come from the same source of truth, so they cannot really contradict. If they seem to, someone has reasoned badly.
The five ways
Aquinas gave five arguments from things we observe to a first cause:
- Motion: everything that moves is moved by something else; there must be a first, unmoved mover.
- Cause: every effect has a cause; there must be a first cause.
- Contingency: things that might not have existed need a necessary being.
- Degrees: more and less good point to a highest good.
- Design: things without minds act for goals, so something with a mind directs them.
Natural law
Humans can know by reason basic moral rules, such as preserve life and seek truth. Just human laws must agree with this natural law.
The crisis of the 14th century: Ockham and the split
In the 1300s Europe faced plague, war and arguments inside the Church. Philosophers began to doubt the big synthesis of Aquinas.
- John Duns Scotus (c. 1266–1308) stressed God's free will and the uniqueness of each individual thing.
- William of Ockham (c. 1287–1347): Ockham's razor: do not add more causes or entities than you need. He was a nominalist: universals are only names; only individual things are real.
- Many now held that faith cannot be proved by reason, so theology and philosophy began to separate.
This opened space for observation-based science, the Renaissance and later the scientific revolution.
Key formulas and definitions
- Faith = trust in revealed truth; Reason = truth worked out by thinking and evidence
- Augustine: 'believe in order to understand'; inner illumination
- Scholastic method: question → objections → answer → replies
- Anselm: God = that than which nothing greater can be thought
- Aquinas: reason (ground floor) + faith (upper floor); five ways; natural law
- Ockham's razor: do not multiply entities beyond necessity
- Timeline: Augustine c. 400 → Boethius 524 → Avicenna c. 1020 → Anselm c. 1078 → Averroes c. 1180 → Aquinas c. 1265 → Ockham c. 1320
Worked examples
1. Put these in time order: Aquinas, Augustine, Ockham, Anselm.
Augustine (354–430) → Anselm (1033–1109) → Aquinas (1225–1274) → Ockham (c. 1287–1347).
2. Write a scholastic outline for 'Is it right to lie to protect a friend?'
Question: is it right to lie to protect a friend? Objections: (1) friendship is good, (2) the lie may prevent harm. Answer: a lie damages trust; seek a truthful way to protect them, such as staying silent. Replies: (1) friendship needs trust, which lies break; (2) harm can often be prevented without lying.
3. How does the first way of Aquinas use a chain of dominoes?
Each domino falls only because the one before pushed it. If there were no first push, none would fall. Since things do move, there must be a first mover that is not itself moved.
4. A light in a house goes off. Explanation A: the bulb blew. Explanation B: the bulb blew, and invisible spirits switched the fuse too, then switched it back. Which does Ockham's razor prefer?
A. Both explain what we see, but B adds extra unseen causes that are not needed.
5. Why are Avicenna and Averroes important for Aquinas?
They kept and explained Aristotle's work. When their writings and Aristotle were translated into Latin, Aquinas could use Aristotle and their commentaries to build his system.
6. What did Gaunilo say against Anselm's argument?
With the same logic one could 'prove' that the greatest possible island exists, which seems absurd. So something may be wrong with moving from an idea to real existence.
Common mistakes
- Thinking medieval thinkers rejected reason. Most used reason very carefully and saw it as a gift.
- Forgetting Islamic and Jewish philosophers. Without them much of Aristotle would not have reached medieval Europe.
- Saying Ockham's razor means 'the simplest idea is always true'. It says: do not add causes you do not need.
- Mixing up Augustine (c. 400, inner light, Plato) and Aquinas (c. 1265, Aristotle, five ways).