In this paper, I set out to argue in favour of a philosophical posthumanist and Nietzschean reading of Ira Levin's This Perfect Day while demonstrating how transhumanism isunbefitting of being called a Nietzschean theory. I will do this by establishing Chip, the protagonist, as a posthuman and being on the path of the 'Overhuman' whereas Wei, the antagonist, will be illustrated as Chip's intended counterpart the Last Human. Through explaining 'Transhumansim' and connecting the field to Wei, I will showcase a new way of reading transhumanist ideology, namely 'Weiism'. The polar opposite in characters of 'Overhuman' and 'Last Human' will argue in favour of the Nietzschean paradoxical, as part of philosophical posthumanism. Amor fati and the eternal recurrence become posthumanist narrative tools through their weaving into the posthuman narrative of Chip. My argument is that by making philosophical posthumanism more existentialist in nature, it becomes simpler to argue against nihilistic and totalitarian tendencies of worshipping technology. Finally, it is the spiralling motion forward as a mix between the Nietzschean, eternally cyclical re-inventing of oneself and the posthumanist consideration for the future which makes for a literary combination of the two fields of study.