QuestionsWhy is there something rather than nothing?Nothing would be simpler: there must be a reason
Why is there something rather than nothing?There is a reason

Nothing would be simpler: there must be a reason

Leibniz's ultimate question

Gottfried Wilhelm Leibniz 1646 · 1716We live in the best of all possible worlds.
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What it claims

There is something rather than nothing because a necessary being exists, the ultimate reason of things, which Leibniz calls God.

Why

Nothing would be simpler, and the chain of contingent things never explains its own existence: the reason lies outside it.

The same idea through history
Gottfried Wilhelm Leibniz1697On the Ultimate Origination of Things: the sufficient reason of existence is found neither in any particular thing nor in the whole aggregate of things.
Gottfried Wilhelm Leibniz1714Principles of Nature and Grace: the question is asked in so many words, then answered (God).
Gottfried Wilhelm Leibniz1714The same idea, applied to the contingency of the world, is studied in detail in the argument from contingency (question God).
In short

"Nothing would be simpler: there must be a reason" is an argument by Gottfried Wilhelm Leibniz (Principles of Nature and Grace, 1714, § 7-8; On the Ultimate Origination of Things, 1697, 1697) on the question "Why is there something rather than nothing?" (answer: there is a reason). Its claim: There is something rather than nothing because a necessary being exists, the ultimate reason of things, which Leibniz calls God. According to AskPhilosophy's logic check (Z3 solver), the argument is valid only if one grants a premise the author leaves unstated (P4). AskPhilosophy presents 3 objections, 0 of them with a documented reply, and the original text behind each premise, checked word for word.

Principles of Nature and Grace, 1714, § 7-8; On the Ultimate Origination of Things, 1697
Valid with an implicit premise

Why is there something rather than nothing? For Leibniz, this is the first question we are entitled to ask, because nothing would be simpler and easier than something: existence is therefore not obvious. If nothing happens without a reason, the reason for the world's existence cannot be inside the world itself, even going back without end. It must lie in a necessary being, which carries the reason of its existence in itself.

P1Principle of sufficient reason: nothing takes place without sufficient reason, that is, one could always say why things are so and not otherwise.
P2Nothing would be simpler and easier than something: the existence of the world is therefore not obvious and calls for a reason.
P3The reason for the universe's existence is not found in the sequence of contingent things: going back from one state to the previous one, however far, takes us no further, since the same question remains.
P4 · implicit premiseThe reason sought must be complete: we need a reason at which we can stop, one that needs no further reason.
P5This reason therefore lies outside the sequence of contingent things, in a necessary substance that carries the reason of its existence in itself.
There is something rather than nothing because a necessary being exists, the ultimate reason of things, which Leibniz calls God.

click a premise to reject it

If you accept every premise, logic forces you to accept the conclusion. So the debate is about the premises.
Checked by a logic solver: the premises cannot all be true while the conclusion is false.
Without the implicit premise: Without P4, the computer finds a case where the principle of reason holds, where the sequence of things does not contain its own reason, but where we are content with a partial explanation: no necessary being is then required.
Valid with P4, which Leibniz leaves almost in the shadows: he writes that otherwise "we should not yet have a sufficient reason with which we could stop". Without it, we could stop at a sequence of things with no complete reason and the conclusion would not follow. The debates concern P1 (is the principle true without exception?), P3 (does the whole need a reason beyond its parts?) and the very notion of a necessary being (P5).
Analogy. A geometry book copied forever from another book. Each copy is explained by the previous one, but we never learn why there are books rather than nothing. This is Leibniz's own example (On the Ultimate Origination of Things).

Objections

3

Each objection is a conversation: click to see who replies and where the debate stands.

Hume (Cleanthes, in the Dialogues) 1779 · attacks premise 5

The idea of a being whose non-existence would be contradictory makes no sense: whatever we conceive as existing, we can also conceive as not existing. And if something could be necessary, why not the material universe itself? In an endless chain, each part is caused by the one before: where is the difficulty?

no reply
see the argument
No reply possible: objection raised in 1779, after the author's death (1716).
The debate goes on (our summary) Leibniz died in 1716; Hume wrote the Dialogues around 1750-1776. A defender of the principle of reason answers that explaining each part by another does not say why there are parts rather than nothing: see Hume's argument for the rest of the debate.
Where the debate stands (our summary)The core disagreement: does it make sense to say a being exists necessarily? And must the whole be explained in addition to each part? Neither side has convinced the other.
Bertrand Russell 1948 · attacks premise 1

Russell refuses to admit that the universe as a whole must have a cause. For him, the universe is just there, and that is all: we draw the notion of cause from observing particular things, and nothing shows that it holds for the total.

no reply
see the argument
Leibniz did reply, but that text is not yet in our corpus.
Where the debate stands (our summary)Russell and Father Copleston, who defends Leibniz's argument, part ways on this point without settling it (see Russell's argument). It is a disagreement about the reach of the principle of reason, which Russell judges unfounded.
Peter van Inwagen 1996 · attacks premise 2

Summary: van Inwagen argues that the probability of nothing is zero. There would be only one way for the world to be empty, against infinitely many ways of being filled, and nothing favours one over another. If so, nothing was not "simpler" or more probable, and the existence of something is not a surprise to be explained.

no reply
Leibniz did reply, but that text is not yet in our corpus.
Where the debate stands (our summary)This reply assumes that one can speak of probabilities for possible worlds, which is itself disputed. Open point: no widely accepted answer.
What today's voices say
Defend it
Philip GoffHe thinks there must be an explanation for why there is something, a being that explains its own existence, but sees no reason to give it the traits of the traditional God.