One of the best-selling books published by Harvard University Press, Philosophy in a New Key communicated philosophical thinking about signs and symbols to a wide readership and made work in this area available to nonspecialists. Going through several editions, the book remained in print more than half a century after it first appeared, regularly appearing on required or recommended reading lists for college courses in such diverse disciplines as general philosophy, linguistics, English, anthropology, and art.

Professional philosophers have sometimes regarded Philosophy in a New Key as a popularization of the ideas of Whitehead, Cassirer, and Wittgenstein. It has been criticized for its reliance on the early Wittgenstein’s “picture theory” of language, a theory Wittgenstein himself apparently rejected in his later work. Some critics have also objected to Langer’s portrayal of human history as a march of progress, from the folktales and emotional reactions of “primitive savages” to the sophisticated abstractions of “civilized people.”

Langer herself presented her book as an introduction to the “new key” of philosophers of symbolism. Nevertheless, it was an effective synthesis of many different thinkers. Moreover, Langer herself struck a new key in the attention she gave to nondiscursive, nonrational forms of thought. She was also an early exponent of the idea that shared symbols create human communities and that what people can know depends on what symbols are available to them. This view of the symbolic nature of community has become a common one among social scientists, and the prominent anthropologist Clifford Geertz acknowledged Langer’s influence.

Among philosophers of art and music, Langer’s ideas are widely known but not widely accepted. However, respect for her theory of music has been growing among philosophers of music. In his book The Corded Shell (1980), the influential theorist Peter Kivy acknowledged similarities between Langer’s ideas and his own ideas on expressiveness in music. Others, such as philosopher of music Lars-Olof Åhlberg, have recognized Langer’s contribution to the philosophy of music.