Task: Text Categorization
Input (English): This man discussed phrases which describe objects we are not acquainted with in his essay On Denoting. He argued that objects are inferred by logical constructs that are formed from quanta of sensation in his 1918 lectures on Logical Atomism. This author of Why I am not a Christian found a paradox in Freges theory, wherein a set cannot be a member of a set of all sets that are not members of themselves. For 10 points, identify this philosopher who collaborated with Whitehead on the Principia Mathematica.
Output (English): Social Science