 Kierkegaard developed this problem in the context of his radical approach to Christian faith; Nietzsche did so in light of his thesis of the death of God. Subsequent existential thought reflects this difference: while some writers—such as Sartre and Beauvoir—were resolutely atheist in outlook, others—such as Heidegger, Jaspers, Marcel, and Buber—variously explored the implications of the concept “authentic existence” for religious consciousness. Though neither Nietzsche’s nor Kierkegaard’s thought can be reduced to a single strand, both took an interest in what Kierkegaard termed “the single individual.” Both were convinced that this singularity, what is most my own, “me,” could be meaningfully reflected upon while yet, precisely because of its singularity, remain invisible to traditional philosophy, with its emphasis either on what follows unerring objective laws of nature or else conforms to the universal standards of moral reason. A focus on existence thus led, in both, to unique textual strategies quite alien to the philosophy of their time.