This dissertation articulates Merleau-Ponty's philosophy of nature in relation to the existential condition of "natality," as defined by Arendt. Where Heidegger emphasizes mortality in his post-metaphysical ontology, these investigations follow Merleau-Ponty and Arendt who emphasize that humans are not only mortals but "natals," beings who begin. The project has a twofold aim: 1. to present an exegesis of Merleau-Ponty's oeuvre with a special emphasis on the Nature Courses and 2. to sketch out a natal ontology in its own right. This ontology depends on Merleau-Ponty's methodological advancement beyond genetic phenomenology to generative and "poetic" phenomenology, a practice that incorporates historicity and expressivity. He offers a critique of science, particularly of evolutionary biology, that is shown to be relevant in a contemporary context. His natal ontology co-emerges with an ethical standpoint; he shows that a natural prereflective relation to a plurality of others, rather than only a single other, fundamentally conditions human existence. In a natal ontology, knowledge depends on being born with others, through a co-naissance of one's worldly situation.