This paper characterizes various responses to the question, 'Why does our universe exist?' Some responses- that the question is senseless, that the existence of our universe is logically necessary- are implausible. Adjudication between more plausible responses requires us to evaluate the argument from the 'fine-tuning' of the universe, a refurbished version of the argument from design that appeals to cosmology rather than biology. The evidence of fine-tuning should lead us to adopt, albeit provisionally, cosmological fecundity, the hypothesis that there exist (...) many universes of varying characters. The existence of our universe is thereby rendered less surprising. This is to be preferred both to the theistic hypothesis and to the view that the existence of our universe requires no explanation. (shrink)

I begin by giving reasons to accept the block-universe view, the strongly supported by physics view that we live in a four-dimensional world. According to it, the past and the future are as real as the present. As a result, it seems that the future is determined in the sense that what will be the case will necessarily be the case. In the dissertation, I examine whether we have to accept this consequence. I show that we do not have to (...) bite the bullet: the future might be both real and contingent. I first start to consider modal realism (possible futures are real) as a possible solution. However, I propose then another account, actualist (positing the reality of only one possible world: the space-time we live in). This solution relies on a conventionalist theory about metaphysical modality (Sidelle, 1989). It states that modal modality is purely conventional. In combination with a realist interpretation of natural modality (causal and/or nomological), this framework allows me to propose that the future is conventionally closed and naturally contingent. In this view, the necessity of the future holds in virtue of linguistic conventions and then is conventionally necessary. But this is a distinct phenomenon from the natural contingency of the future: the future is naturally contingent because there are mind-independent probabilistic relations holding between the present and the future. This solution has strong consequences: most importantly, an anti-realist view about ordinary objects and physical particles. I end up by presenting and arguing in favour of the general image of the world that comes out from these views. (shrink)