Task: Text Categorization
Input (English): This philosopher wrote that "purity of heart is to will one thing" and penned a paean to his mother tongue in Stages on Life's Way. This man admired Socrates as a "noble, simple wise man" in his Christian Discourse. This man argued that "subjectivity is truth" in the sequel to his earlier Philosophical Fragments, and in another work compares the ethical dilemmas facing Agamemnon and Abraham. For 10 points, name this "father of existentialism" who wrote Either/Or and Fear and Trembling.
Output (English): Social Science