Philosopher who wrote Thus Spoke Zarathustra (9)
I believe the answer is:
nietzsche
(Other definitions for nietzsche that I've seen before include "Influential German existentialist philosopher" , "Friedrich -, nineteenth century German philosopher" , "German poet" , "19th century German philosopher who divided mankind into master class and herd" , "German philosopher, d. 1900, noted for his concept of superman" .)