Language in Thought and Action is a book on semantics by Samuel Ichiye Hayakawa, based on his previous work Language in Action published in 1939. Early editions were written in consultation with different people. The current 5th edition was published in 1991. It was updated by Hayakawa's son, Alan R. Hayakawa and has an introduction by Robert MacNeil. Its Library of Congress control number is 92033105.The book has sold over one million copies and has been translated into eight languages.