Why someone rather than no one?

The question of "why there is someone rather than no one" compels us to revisit Leibniz's question of "why there is something rather than nothing", as implied by his principle of sufficient reason, full determination, and trust it provides. 1) We will pursue that implication in some detail until we arrive at the dimension that Leibniz attributes to someone, and this someone's properties within his system. 2) On the basis of a succint historical consideration that contrasts Descartes with the Neoplatonic background (animism), and reviews Spinoza's reaction (monism and immanentism) to his predecessor (dualism), I will attempt to illustrate Leibniz's (transcendent) position on the question that guides us. 3) But the question is still pertinent today, vis a-vis certain positions-naturalism or nihilism, for example-that would contend that there is no one rather than someone. 4) To this end, we will assess the extent to which Leibniz helps us, on the one hand, and, on the other, just how far we ought to stray from him, or from a traditional interpretation of his concept of reason.