Periods in the History of Ideas and Key Philosophers
Periods in the History of Ideas
Pre-Socratic period
Classical period
Hellenistic period (broadest)
Hellenistic period (proper)
Late Antiquity
Middle Ages (ca. 600-450 BCE) (ca. 450-322 BCE) (ca. 322 BCE - 400 CE) (ca. 322 BCE - 100 CE) (100-400 CE) (ca. 400-1400 CE)
Alberto describes the Middle Ages as "began at 4:00a.m. & lasted till 2 p.m."
This metaphor implies a span of 10 hours equating to approximately 1000 years (from ca. 400 CE-1400 CE)
Renaissance (ca. 1400-1600 CE)
The Renaissance characterized as the period that "named" the Middle Ages (aka "the Medieval period")
Key Dates - Antiquity to Middle Ages
70 CE
Christianity "splits" from Judaism (Fall of Temple)
313 CE
Christianity is legalized in the Roman Empire by Constantine (one of many, but Constantine takes special interest)
330 CE
Constantine, pressed by Germanic tribes, relocates Rome to (modern-day) Turkey, renaming Byzantium to "Constantinople" (now known as Istanbul).
Christianity is established as the official religion of the Roman Empire.
The Roman Empire is divided into "Eastern" and "Western" halves.
476 CE
The Germanic king Odoacer deposes the last Western Roman emperor, sending imperial insignia to the Eastern Roman emperor.
Closure of Plato's Academy.
529 CE
The educational legacy continues despite challenges.
1453 CE
The Eastern Roman Empire falls to the Turks.
The Medieval "Project"
Medieval European philosophy assumes the truth of Christianity.
The main project of medieval philosophy is the reconciliation of faith and reason. Key questions include:
Do faith and reason ever conflict?
When they do, which truth is "more true"?
Can some or all truths of faith (especially regarding God) be proved using reason alone?
Do faith and reason operate in completely separate domains?
How should pagan philosophers (such as Plato, Aristotle) be regarded?
Medieval Philosophy
Three notable medieval philosophers:
(St.) Augustine (354-430 CE)
(St.) Anselm (1033? - 1109 CE)
(St. Thomas) Aquinas (1225-1274 CE)
Augustine (354 - 430)
Origin: North Africa, Berber heritage, family very Roman, spoke Latin.
Religious Background:
His mother was a Christian believer, while his father was not.
Initially preferred classical Roman writers to the Bible, which he deemed less intellectually satisfying.
Religious Journey:
Converted to Christianity after exploring:
Manicheeism (dualistic Persian religion)
Neo-Platonism (dualistic philosophical "religion")
Role:
Became a bishop and influential writer; known as the "baptizer of Plato."
Interpreted Christian doctrine through a Platonic lens unless directly conflicting.
Best-Known Works:
Confessions: The first autobiography in the West.
City of God: Written during the decline of the Western Empire (Sack of Rome - 410 CE).
Defends Christianity against claims of being responsible for Rome’s failure, arguing instead that Christianity contributed to Rome's successes.
Concept of the real City of God as a spiritual, not a physical, kingdom, highlighting classic Platonic dualism.
Anselm (11th C)
Birthplace: Italy.
Later became Archbishop of Canterbury, hence referred to as "Anselm of Canterbury" to differentiate from another Anselm.
Reputation in Philosophy:
Best known for the Ontological Argument for the existence of God (examined in a separate discussion).
A noteworthy philosophical contribution, intriguing despite being debated as flawed.
Aquinas (1225-1274)
Birthplace: Italy.
Context: Emergence of universities in Europe; Aristotle’s works returned to Europe through Islamic scholars.
Philosophical Influence:
Found Aristotle compatible with Christian doctrine.
His major work, Summa Theologica, applies Aristotelian language and methods to explain Christian concepts.
Known for the Five Ways, which are Aristotelian-style proofs for God’s existence, paralleling Augustine’s work for Plato.
The God of Western Monotheism
Attributes of God:
Omnipotent: All-powerful.
Omniscient: All-knowing.
Omnipresent: Present everywhere.
Omnibenevolent: All-good.
Infinite, Perfect, Changeless, Ultimate.
Defining God:
Anselm defines God as "a being greater than which none can be imagined."
This definition encompasses all the omni-properties ascribed to the monotheistic God.
Anselm asserts that upon understanding this definition, one must concede the existence of such a being.
The Proof (1)
Initial Definition:
Anselm defines God as "a being greater than which none can be imagined" (designated as G).
The existence of G as a concept in the mind is universally recognized.
Two Cases:
Case 1: Non-believer's view - G exists only as a concept in the mind.
Case 2: Believer's view - G exists in the mind and in reality.
Disproving Case 1: Using proof by contradiction.
Assuming Case 1 (non-believer is correct).
Imagining a second being, G2, which has all properties of G with the addition of reality.
Comparing the two: G2 is greater than G.
This creates a logical contradiction as G2 cannot exist if G is the greatest conceivable being.
Therefore, Case 1 is false; thus, Case 2 must be true—G exists.
The Proof (2): Ontological Argument
Definition: Ontological arguments start from concepts and derive existence.
Gaunilo's Challenge:
Gaunilo, a monk, challenges Anselm's logic by using a similar structure to claim that a perfect island (PI) must exist.
His structure is stated as “an Island greater than which none can be imagined.”
Gaunilo's Refutation (1):
Two cases:
Case 1: Non-believer’s view - PI exists only as a thought.
Case 2: Believer's view - PI exists conceptually and in reality.
Gaunilo's Refutation (2): Following the proof by contradiction:
Assume PI exists only in thought.
Imagining a second island P12 with all properties of PI plus the property of existing.
Compare the two: P12 is greater than PI.
This results in a logical contradiction—there cannot be an island greater than PI.
Therefore, Case 1 cannot hold, which leads to Case 2 being true—PI exists. Yet, this leads to absurdity since no such island exists.
Anselm's Response:
Anselm posits that there is no common idea for "Perfect Island" as people’s perceptions of it vary.
Conversely, a “Perfect Being” universally maintains properties associated with monotheism. Thus, the argument remains valid for God but not for PI.
Aquinas & the A Posteriori
Aquinas in Summa Theologica explores the existence of God through rational analysis, rejecting the Ontological Argument.
Offers Five arguments based on evidence from the world (a posteriori) including:
The Cosmological Argument(s): Start with the existence of the world, positing that something exists beyond it to cause this existence.
First Three Arguments (All cosmological):
The Argument from Motion: Observes changes in the world, stating nothing can cause its own motion.
The Argument from Efficient Cause: Every effect has a cause. An infinite regression of causes is impossible.
The necessity of a First Cause — an Uncaused Cause, identified with God.
Argument from Causation
Observations lead us to recognize an existence of causes and effects.
A cause cannot cause itself; this necessitates that every effect has a cause.
Establishment of a causal chain emerges: Cause → Effect → Cause → Effect…
An infinite regression of causes is untenable; without a First Cause, there would be no effects today.
Thus, we conclude a First Cause, defined as God.
Argument from Motion
Observations confirm movements and changes in the world.
Nothing can initiate its own motion; a mover must already exist in a state of motion.
A chain of movers can be established: Mover → Thing Moved → Mover → Thing Moved…
An infinite regression of movers is not possible; absence of a First Mover leads to no movements today.
Consequently, a Prime Mover is inferred—identified as God, embodying complete actuality without mere potentiality.