This thinker's essay "On 
This thinker's essay "On the Nature of Acquaintance" cites William James' proposal that substances are not intrinsically physical or mental, but differ only in their context. This champion of neutral monism was criticized in a paper by P.F. Strawson that posits sentences like "the table is covered with books." He criticized Meinong's theory of objects and Frege's idea of sense and reference in his essay "On Denoting." Godel's incompleteness theorem dealt a blow to this man's attempt to formulate axioms from which all mathematical truths could be derived. For 10 points, name this philosopher who wrote Principia Mathematica with Alfred Whitehead.
This thinker's essay "On the Nature of Acquaintance" cites William James' proposal that substances are not intrinsically physical or mental, but differ only in their context.