01The data
Contingency, not temporal beginning, is what demands explanation — so the argument works even if the universe is eternal, and carries no commitment about its age.
Cosmological
The Contingency Argument (Leibniz)
Leibniz asked in 1697 why there is something rather than nothing, and answered that no chain of contingent things can supply its own explanation — the series must terminate in a being that exists by the necessity of its own nature.
high confidencePhilosophical
THE CLAIM
Leibniz asked in 1697 why there is something rather than nothing
- 1ContingencyThe data
- 2The principle of sufficient reasonThe data
- 3A chain of contingent explanationsThe record
- 4If the universe is all physical realityThe data
- 5Aquinas's Third WayThe record
- 6Exodus 3The record
WHERE IT STANDS
Firmly established
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The span, dated
c. 1270
Aquinas's Third Way
Summa Theologiae Ia, q.2, a.3 reasons from possibility and necessity rather than from a first moment — and Aquinas held that the world's temporal beginning is known by revelation rather than by reason.
1697
Leibniz poses the question
"On the Ultimate Origination of Things": why is there something rather than nothing? Tracing the physical series backwards does not answer it, because each prior state is as contingent as the one it explains.
1714
Principles of Nature and Grace §7
Leibniz states the principle of sufficient reason in the form the modern argument still uses.
2006
Pruss defends the principle
The Principle of Sufficient Reason: A Reassessment (Cambridge). His central point is practical: science, criminal investigation and ordinary reasoning all proceed on the assumption that things have explanations, and no one applies it selectively except when a conclusion is unwelcome.
2009
The rigorous modern statement
Alexander Pruss, "The Leibnizian Cosmological Argument," in The Blackwell Companion to Natural Theology.
THE CLAIM
The question
Gottfried Wilhelm Leibniz posed it in "On the Ultimate Origination of Things" (1697) and again in the Principles of Nature and Grace (1714), section 7: why is there something rather than nothing? He is explicit that the question is not answered by tracing the physical series backwards, because each prior state is as contingent as the one it explains.
The argument in its modern form
1. Everything that exists has an explanation of its existence, either in the necessity of its own nature or in an external cause. 2. If the universe has an explanation of its existence, that explanation is God. 3.
The universe exists. 4. Therefore the universe has an explanation of its existence. 5. Therefore that explanation is God.
The form is valid. Premise 1 is the principle of sufficient reason; premise 2 does the theological work.
The decisive difference from kalam
This argument does not need the universe to have begun. Even an eternally old universe would still be contingent — it could have been otherwise, or not at all — and contingency is what demands explanation, not youth.
That is why Aquinas's Third Way (Summa Theologiae Ia, q.2, a.3) reasons from possibility and necessity rather than from a first moment, and why Aquinas held that the world's temporal beginning is known by revelation rather than by reason. The contingency argument therefore carries no commitment whatever about the age of the universe.
Why the universe looks contingent
The constants of physics could have taken other values. The particle content could have differed. Cosmologists routinely model universes with other parameters, which is an admission that this one is not self-explanatory.
A thing whose properties could have been otherwise does not contain its own reason for being.
Why the explanation must be god
If the universe is all of physical reality — space, time, matter, energy — then whatever explains it is not physical, not spatial and not temporal. Alexander Pruss's chapter "The Leibnizian Cosmological Argument" in The Blackwell Companion to Natural Theology (2009) is the rigorous version; the shortlist of non-physical, non-temporal candidates capable of explaining a physical world is a mind.
The principle of sufficient reason
Everything hangs on premise 1. The strongest defence is Pruss's The Principle of Sufficient Reason: A Reassessment (Cambridge, 2006). His central point is practical: science, criminal investigation and ordinary reasoning all proceed on the assumption that things have explanations, and no one applies the assumption selectively except when a conclusion is unwelcome.
What scripture calls this being
Exodus 3:14 gives the divine name as I AM THAT I AM — being itself, self-existent, not derived. Acts 17:28 says in Him we live and move and have our being. Revelation 4:11 grounds existence in God's will: all things were created for His pleasure.
Hebrews 1:3 has the Son upholding all things by the word of His power — present tense, continuous.
That is the contingency argument's conclusion in the vocabulary of worship: everything else is on loan.
WHERE IT STANDS
The state of the debate
high confidence
The argument is in good health in professional philosophy of religion; Pruss, Richard Gale, Joshua Rasmussen and Robert Koons have all published defences in the last two decades. The chief critics are Graham Oppy and Peter van Inwagen, and the dispute turns on two questions: how strong a version of the principle of sufficient reason can be defended, and whether a necessarily existing physical reality is coherent. Neither question is closed.
Scripture on this
Exodus 3:14 — I AM THAT I AM — self-existence as the divine name.
Acts 17:28 — In Him we live and move and have our being.
Revelation 4:11 — All things exist and were created because He willed it.
Colossians 1:17 — He is before all things, and by Him all things consist.
Hebrews 1:3 — Upholding all things by the word of His power — sustaining, not merely starting.
Psalm 90:2 — From everlasting to everlasting, thou art God.
John 5:26 — The Father has life in Himself — necessary existence in Johannine terms.
6 pieces of evidence
What this establishes
- 02The data
The principle of sufficient reason is the operating assumption of all science and investigation; suspending it only for the universe is special pleading.
- 03The record
A chain of contingent explanations, however long, never supplies its own reason — each link inherits the debt.
- 04The data
If the universe is all physical reality, its explanation must be non-physical, non-spatial and non-temporal.
- 05The record
Aquinas's Third Way (Summa Theologiae Ia, q.2, a.3) argues from possibility and necessity rather than from a first moment.
- 06The record
Exodus 3:14 names God as self-existent being — precisely the terminus the argument requires.
7 passages
Key verses
Berean Standard Bible
God said to Moses, “I AM WHO I AM. This is what you are to say to the Israelites: ‘I AM has sent me to you.’”
Exodus 3:14
“‘For in Him we live and move and have our being.’ As some of your own poets have said, ‘We are His offspring.’”
Acts 17:28
“Worthy are You, our Lord and God, to receive glory and honor and power, for You created all things; by Your will they exist and came to be.”
Revelation 4:11
“He is before all things, and in Him all things hold together.”
Colossians 1:17
“The Son is the radiance of God’s glory and the exact representation of His nature, upholding all things by His powerful word. After He had provided purification for sins, He sat down at the right hand of the Majesty on high.”
Hebrews 1:3
“Before the mountains were born or You brought forth the earth and the world, from everlasting to everlasting You are God.”
Psalm 90:2
“For as the Father has life in Himself, so also He has granted the Son to have life in Himself.”
John 5:26
THE RECEIPTS
Sources
- Gottfried Wilhelm Leibniz, On the Ultimate Origination of Things (1697)
- Gottfried Wilhelm Leibniz, Principles of Nature and Grace (1714)
- Thomas Aquinas, Summa Theologiae Ia q.2 a.3 (1274)
- Alexander R. Pruss, The Blackwell Companion to Natural Theology (2009)
- Alexander R. Pruss, The Principle of Sufficient Reason (2006)
- Peter van Inwagen, An Essay on Free Will (1983)
- Bertrand Russell & Frederick Copleston, BBC Third Programme debate (1948)
◈Contested pointscontested
- The universe itself may be the necessary being. Nothing in the argument rules out a brute necessary physical reality; if a necessary mind is conceivable, so is necessary matter, and physics has no candidate for a contingency detector.
- A strong principle of sufficient reason collapses modality. Peter van Inwagen argued that if every contingent truth has an explanation, then the conjunction of all contingent truths has one, and that explanation must itself be necessary — which makes every contingent truth necessary. Modal fatalism is too high a price.
- Explaining every part does not require explaining the whole. Hume and later Russell held that once each item in a collection is accounted for, asking for an explanation of the collection is a category mistake — Russell told Copleston on the BBC in 1948 that the universe is just there, and that is all.
- Even a successful argument yields a necessary being, not the God of Scripture. Nothing in it establishes that this being is one, personal, good, or still active.