Nelson Goodman (1906–1998) criticized the idea that similarity existed in the world independently of our linguistic inclinations. Goodman was educated at Harvard, was an art dealer in Boston from 1929 to 1941, and became a Harvard professor in 1968. In his The Structure of Appearance (1951) he developed Rudolf Carnap’s (1891–1970) insights about the logical structure of the world. Later, he came to the conclusion that there are many different world structures, depending on the perspectives of observers. In Fact, Fiction and Forecast (1954) Goodman extended his argument that structure in nature depends on our interests with his famous “grue” example.