Given the task definition and input, reply with output. In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

In one work, this philosopher tells a story about one man leaving his lover in order to preserve the idealized recollections of the past. In another work, this man argues that to become a true self, humans must be conscious of the self and also of the alignment with a higher power. This author of Repetition and [*] The Sickness Unto Death wrote a work in which he claimed the final level of individual existence was the "knight of faith." This writer of Fear and Trembling also wrote about the first two levels of existence using the pseudonyms of A and Judge Vilhelm. For 10 points, name this Danish philosopher who wrote Either/Or.
Social Science