Available for the first time in 20 years, here is the Rudolf
Carnap's famous principle of tolerance by which everyone is free to
mix and match the rules of language and logic. In The Logical
Syntax of Language, Carnap explains how his entire theory of
language structure came to him like a vision when he was ill. He
postulates that concepts of the theory of logic are purely
syntactical and therefore can be formulated in logical syntax.