Why Is There Anything at All?

Foundations

Leibniz's Question

• “Why is there something rather than nothing?” — Leibniz's famous question.
• Everything around us could have been otherwise — or not existed at all.
• So why does anything contingent exist?
• This argument seeks an ultimate explanation for reality.

Key idea: Unlike the Kalam (which asks if the universe began), this asks why a contingent universe exists at all — even if it were eternal.

Source: G. W. Leibniz; modern restatements by Pruss and Koons.

Foundations

Contingent vs Necessary

• A contingent thing might not have existed — you, planets, the universe.
• A necessary thing must exist; it cannot fail to.
• Contingent things call for an explanation beyond themselves.
• The argument asks: what grounds all the contingent things?

Useful fact: The key distinction: contingent (could-have-failed-to-be) vs necessary (could-not-not-be).

Source: Standard philosophy of religion.

The Argument

Spelled Out

• 1. Everything that exists has an explanation — in itself, or in a cause.
• 2. The universe (the sum of contingent things) exists.
• 3. So the universe has an explanation.
• 4. That explanation can't be another contingent thing — so it is a necessary being.

Key idea: From “contingent things need explaining” to “a necessary being grounds them” — that's the core move.

Source: Alexander Pruss, in the Blackwell Companion to Natural Theology.

The Argument

The Principle of Sufficient Reason

• Premise 1 is a form of the Principle of Sufficient Reason (PSR).
• Roughly: there are no brute, utterly unexplained facts.
• We assume something like it constantly — in science and daily life.
• Critics question whether it must hold for absolutely everything.

Useful fact: The argument leans on the idea that reality is intelligible — that things have reasons. Science assumes this every day.

Source: Discussions of the PSR in metaphysics.

The Argument

Why Not an Infinite Chain?

• Even an infinite series of contingent causes is still, as a whole, contingent.
• The whole collection would then lack an explanation.
• So an external, necessary ground is still required.
• Pushing causes back forever never answers “why any at all?”

Common reply: “It's contingent things all the way down” doesn't help — an infinite stack of contingents is still unexplained.

Source: Pruss; classic statements of the argument.

The Conclusion

The Necessary Being

• The explanation must exist necessarily, not contingently.
• It would be the ground of its own existence.
• The argument reasons toward such a being.
• Theists identify it with God; the argument itself stops at “a necessary being.”

Key idea: The argument concludes to a necessary being — naming it “God” takes further steps.

Source: Leibniz; Samuel Clarke.

Objections

Must the Universe Have an Explanation?

• Some reply that the universe is just a “brute fact.”
• Others propose the universe itself might exist necessarily.
• Defenders answer that the universe looks contingent — it could have been different.
• This is the live philosophical battleground.

Common reply: “The universe is just there, unexplained” is a possible answer — but it abandons the intelligibility we assume everywhere else.

Source: The Russell–Copleston debate (BBC, 1948).

Objections

A Fallacy of Composition?

• Critics: maybe each part has a cause, while the whole needs none.
• Reply: a whole made only of contingent parts is itself contingent.
• Defenders argue this particular case isn't a composition fallacy.
• The exchange is technical and ongoing.

Source: Discussion in the Blackwell Companion to Natural Theology.

Honest Limits

What It Does and Doesn't Show

• The argument rests on the contested Principle of Sufficient Reason.
• It reaches a necessary being, not a specific religion.
• Serious philosophers both defend and reject it.
• It is one strand in a wider case, not a standalone proof.

Key idea: It argues for a necessary ground of reality — not, by itself, for the God of any particular faith.

Source: Standard assessments of the argument.

Conclusion

The Big Takeaway

• The contingency argument asks why anything exists at all.
• It reasons from contingent things to a necessary ground.
• Its strength is the demand for ultimate explanation; its pressure point is the PSR.
• A serious argument, distinct from the Kalam, pointing beyond the physical.

In one line: If reality is intelligible all the way down, it ends in something that simply must be.

Source: Leibniz; Pruss; the Blackwell Companion.