Task: Text Categorization
Input (English): This thinker's first work was published while a professor at the University of Halle, and was entitled Philosophie der Arithmetik. His most important contribution to philosophy was considered solipsistic by others, so he attempted to show how individual consciousness can be applied to other minds and history in Cartesian Meditations. His most important idea involved "bracketing existence" in contemplating an object, providing a means of describing "things themselves. "  FTP, identify this German philosopher and author of Ideas: A General Introduction to Pure Phenomenology.
Output (English): Social Science