Simple Sentences, Substitution, and Intuitions - Paperbackby Jennifer M. Saul (Author) The phenomenon of substitution failure is a longstanding focus of discussion for philosophers of language. Substitution failure occurs when a change from one co referential name to another (e. g. from 'Superman' to 'Clark Kent') affects the truth value of a sentence. Jennifer Saul has shown that this can occur even in the simplest of sentences. She presents the first full length treatment of this puzzling feature of