Our presence in the universe is something too bizarre for words. The mundaneness of our daily lives cause us take our existence for granted — but every once in awhile we're cajoled out of that complacency and enter into a profound state of existential awareness, and we ask: Why is there all this stuff in the universe, and why is it governed by such exquisitely precise laws? And why should anything exist at all?
The last question is metaphysically quite interesting. If you're a Lewisian modal realist there is a quick answer: There is something rather than nothing, because it's impossible that there is nothing. According to Lewis it's possible that there is nothing iff there is some possible world where nothing exists. Lewis analyses worlds in such a way that this is the case only if there is some (non-empty) mereological sum u of individuals having no parts. But u has at least one part. Contradiction. See David K. Lewis : On the Plurality of Worlds.
You get the same result, if you accept the biconditional and if you assume that worlds are (represented by) classical first-order models, which by definition have non-empty domains.
"why should anything exist at all?" - Why do people find existence more mysterious or "unexpected" than non existence? in particular since we have evidence of the former and no evidence of the later.
My answer to the question "Why is there something rather than nothing?",
which is roughly the same question as "Why should anything exist at all?" is as follows:
I propose that "something" and "nothing" are just two different words, derived from two different ways of thinking, for describing the same underlying thing: what we've traditionally, and, as I'll try to show, incorrectly, thought of as the "absolute lack-of-all" or "non-existence". I put these phrases in quotes because I try to show by my argument that when we've gotten rid of everything that is traditionally thought to exist, the supposed "absolute lack-of-all" or "non-existence" that's left actually meets a definition of what it means to exist.
A. To start, I think the reason that something exists is that it's a grouping defining what is contained within. The surface of a book, the outlines of a cloud, and the curly braces around a set all define what is contained within and give existence to the thing. Without a grouping defining what is contained within, a thing doesn't exist. Imagine an object that has no surface, for instance. Any thing, A, that exists needs a grouping that ties together whatever is inside into a new existent entity called A.
B. Now, getting back to "nothing", we've always thought that when you get rid of all matter, energy, space/volume, time, abstract concepts as well as all minds to consider this, then what's left is the complete lack-of-all or "nothing". But, I think once we've gotten rid of all that stuff, there's one existent thing we can't get rid of, which is the existent entity that is the supposed "absolute lack-of-all" itself. How can this be? Consider the supposed "absolute lack-of-all". That lack of volume, matter, energy, concepts, minds, time, etc. would be the entirety of all that is present. It would be the all. Entirety and all are groupings defining what is present and contained within. Therefore, what we've previously thought of as the "absolute lack-of-all" is, when thought of a little differently, not really the lack of all existent entities; it is itself an existent entity.
If you're interested, there's a better explanation at my website at: