I. A. Richards, University Professor Emeritus and one of the founders of modern literary theory, died Friday in England. He was 86 years old.

Richards' work in the '20s--especially his books "The Meaning of Meaning" and "Principles of Literary Criticism"--turned recent literary criticism toward linguistics, semantics and theories of meaning.

"He was a philosopher of language," Jerome H. Buckley, Gurney Professor of English Literature, said yesterday. "He was at times a difficult and abstruse critic--he built bridges between philosophy and literary theory," he added.

Richards was a lecturer in English from 1939 to 1944, when he became a University Professor.

In the '30s Richards became a proponent of Basic English, a simplified form of the language designed to be learned quickly. He taught in China from 1929 to 1931, and returned there last spring to help develop a teacher-training program.

In "Practical Criticism," Richards developed a theory of poetic meaning and understanding based on poem critiques by students who did not know whose work they were discussing.

Richards was an avid mountaineer as well.

He is survived by his wife, Dorothea, and two brothers.