Task: Text Categorization
Input (English): This author of ""On Denoting"" described the reasoning behind his atheism in the lecture ""Why I Am Not a Christian. "" That a set containing all sets not members of themselves cannot be a member of itself is known as this man's paradox. For 10 points, name this English philosopher who collaborated with Alfred North Whitehead on the three volume Principia Mathematica.
Output (English): History