Some of his works include the article "The Nature and Reality of Objects of Perception" and "Proof of an External World," both attempts to refute idealism and promote his version of realism.  
The perplexity involving the assertion of what is expressed by conjunctions is discussed in his namesake paradox.  Some of his works include the article "The Nature and Reality of Objects of Perception" and "Proof of an External World," both attempts to refute idealism and promote his version of realism.  This belief culminated in his 1903 "The Refutation of Idealism," though he is better known for another 1903 work that asserted that good was indefinable and unanalyzable as per his naturalistic fallacy.  FTP, identify this British philosopher and author of the Principia Ethica.
The perplexity involving the assertion of what is expressed by conjunctions is discussed in his namesake paradox.  
George Edward Moore