Why there is anything at all

The questions pertaining to "why there is anything at all?", or, "why there is something rather than nothing" has been raised or commented on by philosophers including Gottfried Wilhelm Leibniz, Ludwig Wittgenstein, and [[Martin Heidegger]] – who called it "the fundamental question of [[metaphysics]]".
Overview.
The question is posed comprehensively, rather than concerning the existence of anything specific such as the universe or [[multiverse]], the [[Big Bang]], [[mathematics|mathematical laws]], [[physical law]]s, time, consciousness, or [[God]]. It can be seen as an open [[metaphysical]] question. 
[[File:Monad.svg|thumb|The circled dot was used by the Pythagoreans and later Greeks to represent the first metaphysical being, the [[Monad (philosophy)|Monad]] or [[the Absolute]].]]
On causation.
The ancient Greek philosopher [[Aristotle]] argued that everything must have a cause, culminating in an ultimate [[uncaused cause]]. (See [[Four causes]])
[[David Hume]] argued that, while we expect everything to have a cause because of our experience of the necessity of causes, a cause may not be necessary in the case of the formation of the universe, which is outside our experience.
[[Bertrand Russell]] took a "[[brute fact]]" position when he said, "I should say that the universe is just there, and that's all."
Philosopher [[Brian Leftow]] has argued that the question cannot have a causal explanation (as any cause must itself have a cause) or a contingent explanation (as the factors giving the contingency must pre-exist), and that if there is an answer it must be something that exists necessarily (i.e., something that just exists, rather than is caused).
Philosopher William Free argues that the only two options which can explain existence is that things either always existed or spontaneously emerged. In either scenario, existence is a fact for which there isn't a cause. 
Explanations.
[[Gottfried Wilhelm Leibniz]] wrote:
Philosopher of physics [[Dean Rickles]] has argued that numbers and mathematics (or their underlying laws) may necessarily exist.
Physicist [[Max Tegmark]] wrote about the [[mathematical universe hypothesis]], which states that all mathematical structures exist physically, and the physical universe is one of these structures. According to the hypothesis, the universe appears fine-tuned for intelligent life because of the anthropic principle, with most universes being devoid of life.
Criticism of the question.
Philosopher [[Stephen Law]] has said the question may not need answering, as it is attempting to answer a question that is outside a spatio-temporal setting, from within a spatio-temporal setting. He compares the question to asking "what is north of the [[North Pole (disambiguation)|North Pole]]?" Noted philosophical wit [[Sidney Morgenbesser]] answered the question with an [[apothegm]]: "If there were nothing you'd still be complaining!", or "Even if there was nothing, you still wouldn't be satisfied!"
Physics is not enough.
Physicists such as [[Stephen Hawking]] and [[Lawrence Krauss]] have offered explanations that rely on quantum mechanics, saying that in a [[quantum vacuum|quantum vacuum state]] [[virtual particles]] and [[spacetime]] bubbles will spontaneously come into existence. Nobel Laureate [[Frank Wilczek]] is credited with the aphorism that "nothing is unstable." However, this answer has not satisfied physicist [[Sean M. Carroll|Sean Carroll]], who argues that Wilczek's aphorism accounts merely for the existence of matter, but not the existence of [[quantum state]]s, space-time or the universe as a whole.
God is not enough.
Philosopher Roy Sorensen writes in the "[[Stanford Encyclopedia of Philosophy]]" that to many philosophers the question is intrinsically impossible to answer, like [[squaring the circle|squaring a circle]], and even God does not sufficiently answer it: 
Argument that "nothing" is impossible.
The pre-Socratic philosopher [[Parmenides]] was one of the first Western thinkers to question the possibility of nothing. Many other thinkers, such as [[Bede Rundle]], have questioned whether [[nothing]] is an ontological possibility. Nothing might be a human concept that is only a [[Construct (philosophy)|construct]] and inappropriate for a description of a possible state, or absence of state.
The contemporary philosopher Roy Sorenson has dismissed this line of reasoning. Curiosity, he argues, is possible "even when the proposition is known to be a [[necessary truth]]." For instance, a ""[[reductio ad absurdum]]" proof that 1 − 1/3 + 1/5 − 1/7 + … converges to π/4" demonstrates that not converging to π/4 is impossible. However, it provides no insight into "why" not converging to π/4 is impossible. Similarly, even if "nothing" is impossible, asking why that is the case is a legitimate question.
External links.
[[Category:Causality]]
[[Category:Concepts in metaphilosophy]]
[[Category:Concepts in metaphysics]]
[[Category:Concepts in the philosophy of mind]]
[[Category:Concepts in the philosophy of science]]
[[Category:Cosmogony|*]]
[[Category:Emergence]]
[[Category:Existentialist concepts]]
[[Category:History of philosophy]]
[[Category:Metaphysical theories]]
[[Category:Metaphysics of mind]]
[[Category:Metaphysics of science]]
[[Category:Ontology]]
[[Category:Philosophical problems]]