The story of eternity is not as simple as a secularization narrative implies. Instead it follows something like the trajectory of reversal in Kant’s practical proof for the existence of god. In that proof, god emerges not as an object of theoretical investigation, but as a postulate required by our practical engagement with the world; so, similarly, the eternal is not just secularized out of existence, but becomes understood as an entailment of, and somehow imbricated in, the conditions of our practical existence.
The sections that follow discuss some of those central figures in modern European philosophy whose views prominently feature some consideration of eternity. I start with Kant in section I. Kant’s critique of speculative theology is well-known, and this hostility would appear to make it unlikely that the eternal, with all its theological baggage, would feature prominently in Kant’s critical philosophy. But in fact Kant’s transcendental idealism endorses no fewer than three different concepts of the eternal, including what turns out to be the most historically influential idea: that practical reason involves a kind of eternal, non-temporal action. Kant shifts this notion of a non-temporal act from its original theological context of god’s actus purus to a practical context, setting the stage for Schelling’s and Kierkegaard’s later development of this theme. Before detailing this trajectory however, section II is devoted to Hegel, the philosopher whose radical historicism is perhaps more than any other thinker responsible for making “the nineteenth century preeminently the historical century.”4 Hegel is not fertile soil for the concept of the eternal, but his historicism does turn out, at a crucial moment in the philosophy of nature, to presuppose a certain conception of eternity as an eternal present. Perhaps more importantly for the further development of eternity in nineteenth century thought however is that both Schelling and Kierkegaard situate their views of the eternal in the context of a collective rejection of Hegel. Section III discusses Schelling, who returns to Kant’s conception of non-temporal choice, seeing human capacities for free eternal self-creation as rivaling god’s. Such powers are required, Schelling argues, to resist the sublimation of the individual human person into the blankness of the Absolute. Section IV briefly consider Schopenhauer’s view that the in-itself of everything is an endlessly striving will. Section V concerns Kierkegaard who is strongly committed to the eternal, and indeed criticizes Hegel for compromising his conception of the eternal by thinking it temporally; but he is obsessed by the paradoxical question of our practical “access” to the eternal within a particular temporal moment: the decisive moment, imbued with significance that can turn life around and create a new person, pushing Schelling’s concerns even further. The remaining, shorter sections, present briefer accounts of more recent figures who make important use of some conception of the eternal: Nietzsche’s eternal return (section VI), Agamben’s (1942-) theory of sovereignty (section VII) and finally Alain Badiou’s unapologetic attempt to resuscitate eternity as the condition of revolutionary political change (Section VIII). I end with a concluding meditation (Section IX).