For some months I have been trying to appreciate the question, "why is there something instead of nothing?" This question is asked by Heidegger in his Introduction to Metaphysics, but I began by considering the question as it is answered by Leibniz, and torn open again by Kant (as well as in some other reflections). In my mind I have been working towards a confrontation with Parmenides, who I see as having made some important determinations regarding 'nothing', as he is considered the origin of the principle ex nihilo nihil fit(Out of nothing comes nothing).
My confrontation with Parmenides has been postponed indefinitely, as I have come to realize the importance that Kant's little belabored treatment of 'nothing' in the Critique of Pure Reason. Here I want to provide an opportunity to reflect by challenging the assertion: at least something exists. First I will need to frame this assertion so that the difficulties opened up by Kant can be appreciated.
Even though our experience is entirely of what appears to us, we at least say for ourselves that something more must exist. Concerning this something, even if we can be completely wrong about its character, we at least know it exists. But, what Kant shows in his considerations of the 'problematic' is that really we have no right to even make this claim.
For Kant, to exist is merely a basic determination of object of a possible experience: existence concerns merely the synthetic unity of representations. This being said, if we want to show something existing apart from experience, we are going to have an impossible time of it. Even still, we are confident in claiming that there is something that exists underlying what appears. We may even go so far as to laugh or roll our eyes at those who would deny that at least something exists.
Kant himself remarks that the very term 'appearance' suggests something that appears, and so already is in favor of this existing substrate. However, Kant just as much denies that we can apply the category of existence beyond appearances - at least when we are concerned with what can be known by us - and so it is a belief that we assert when we say that there is a substrate of all experience that has the character of a something.
With the possibility of the 'ground of existence' being the character of nothing we find ourselves at the threshold of nihilism. However, there is no grounds for characterizing the 'ground of existence' as having the character of nothing, either. (Here we are perhaps getting at the heart of Jacobi's misunderstanding when he coined the word 'nihilism' in reference to Kant's Critical Philosophy.) So far, I have implied that there is a character to something as well as nothing; in Kant's thought this character is determined relative to time. The 'ground of existence' must be understood out of relation to the temporal. We may be tempted to suggest that the eternal is what evades time, but it seems that this notion is employed with preference for the character of something, and so I will leave it behind for now.
Kant's term of choice for this domain outside of time is the problematic, which is not 'something' or 'nothing', but is indeterminate if it is of the character of something or nothing, possible or impossible. (It is often the case that impossibility is understood through non-contradiction, and with the problematic we find non-contradiction cannot strictly apply. This is a clue for understanding logic so far as it takes itself to be founded on such principles.) In Kant's work, he seemingly resolves the problematic as quickly as it opens us. He does this by illustrating how we side with 'something' as the character of the problematic due to the constitution of our moral life (that is, not as a moral conclusion, but as the very possibility of our thinking morally).
I take Kant's work showing the relation of the moral to the problematic to be perfectly correct, but I think more can be said in emphasizing the manner in which the problematic is determined in favor of 'something'. The importance of such reflections, I believe, are immeasurable. Keeping the problematic in view helps to show the deficiency in nihilism as well as enthusiasm, while still respecting the difficulties that those views overcome. Also, showing how the moral life settles the matter of the problematic provides for endless amounts of reflection on all domains of thought. In addition, we can also begin to see how language is completely infiltrated with this determination in favor of existence - not in order to reject such infiltration, but to understand it.