William Diver of Columbia University (1921-1995) critiqued the very roots of traditional and contemporary linguistics and founded a school of thought that aims for radical aposteriorism in accounting for the distribution of linguistic forms in authentic text. Grammatical and phonological analyses of Homeric Greek, Classical Latin, and Modern English reveal language to be an instrument whose structure is shaped by its communicative function and by the peculiarly human characteristics of its users. Diver's foundational works, many never before published, appear here newly edited and annotated, with introductions by the editors. The volume presents for the first time to a wide audience the depth and originality of Diver's iconoclastic thought.