The First Cause Argument (Cosmological Argument)

The first cause argument (cosmological argument) reasons that everything that exists must have a cause, and that the chain of causes cannot go back infinitely — there must be a first, uncaused cause, which is God. This lesson explores the argument, its history, and its strengths and weaknesses.

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What is the First Cause Argument?

The cosmological argument (from the Greek kosmos meaning "world" or "universe") can be summarised:

1. Everything that exists has a cause
2. The universe exists, so it must have a cause
3. There cannot be an infinite chain of causes (infinite regress)
4. Therefore, there must be a first cause that is itself uncaused
5. This uncaused first cause is God

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St Thomas Aquinas (1225-1274)

The most famous version was developed by the medieval philosopher and theologian Thomas Aquinas in his "Five Ways." The relevant ways are:

The First Way — The Unmoved Mover

• Everything in motion (change) was set in motion by something else
• This chain cannot go back forever — there must be a first mover that is itself unmoved
• This unmoved mover is God

The Second Way — The Uncaused Cause

• Everything that exists has a cause
• Nothing can cause itself
• The chain of causes cannot be infinite — there must be a first cause
• This first cause is God

The Third Way — Necessity and Contingency

• Everything in the universe is contingent (it depends on something else for its existence and could not exist)
• If everything were contingent, there would have been a time when nothing existed — but then nothing could exist now
• Therefore, there must be a necessary being that does not depend on anything else — God

graph TD
    A["The universe exists"] --> B["Everything has a cause"]
    B --> C["The chain of causes cannot be infinite"]
    C --> D["There must be a First Cause"]
    D --> E["The First Cause is God"]

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The Kalam Cosmological Argument

A version of the argument from Islamic philosophy (developed by scholars like Al-Ghazali):

1. Everything that begins to exist has a cause
2. The universe began to exist (supported by the Big Bang theory)
3. Therefore, the universe has a cause
4. This cause must be outside the universe — it must be God (Allah)

"He is the Originator of the heavens and the earth." (Surah Al-An'am 6:101)

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Strengths of the First Cause Argument

Strength	Explanation
Logical	The argument follows a clear logical chain of reasoning
Supported by science	The Big Bang theory suggests the universe had a beginning — consistent with a first cause
Common sense	We do not see things coming into existence without a cause
Compatible with both faiths	Both Christianity and Islam affirm God as the creator and first cause
Explains existence	It answers the fundamental question: "Why is there something rather than nothing?"

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Challenges to the First Cause Argument

Challenge	Explanation
Who caused God?	If everything needs a cause, what caused God? (Believers respond: God is the uncaused cause — he is eternal and necessary)
Infinite regress	Maybe the chain of causes IS infinite — we cannot prove it must have a beginning
The Big Bang is not proof of God	The Big Bang explains how the universe began, not who caused it — science may eventually explain the origin without God
Hume's objection	Just because events within the universe have causes does not mean the universe itself must have a cause — the "fallacy of composition"
Quantum physics	At the quantum level, some events appear to occur without a cause — challenging the principle of causation
Multiple first causes	Even if there is a first cause, why must it be the God of Christianity or Islam?

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Religious Responses

Challenge	Response
Who caused God?	God is by definition uncaused, eternal, and necessary — he is a different category of being
Infinite regress	An actual infinity is logically impossible — the chain must stop somewhere
Science	Science explains mechanisms, not ultimate purpose; "why" questions remain
Quantum physics	Quantum events may have causes we do not yet understand

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Summary

The first cause argument is a powerful philosophical case for God's existence. It argues that the universe must have a cause, and that this cause must be an eternal, uncaused being — God. While challenges from philosophy and science raise important questions, the argument continues to be influential in both Christian and Islamic thought and addresses the fundamental question of why anything exists at all.

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Worked Example: "So Who Made God?" — A Sixth-Form Debate

Consider this classroom scenario. In a UK sixth-form philosophy class, Year 12 students are debating the cosmological argument. A Catholic student called Theo is defending the argument; a Muslim classmate Amira agrees but uses the Kalam version; an atheist student Ben presses Hume's and Russell's objections. A student with no settled view, Jaya, tries to decide which case is stronger.

Theo (Catholic, uses Aquinas's Second Way). "Everything that exists has a cause. The chain of causes cannot be infinite because you could never actually reach now. Therefore there must be a first cause that is itself uncaused — God. This fits with modern cosmology: the Big Bang shows the universe had a beginning. Before the Big Bang, there was no space, no time, no matter. Something outside the universe — timeless, spaceless, immaterial, and personal — must have caused it. That matches the Christian description of God."