The three-volume "Philosophy of Symbolic Forms" is the outstanding work in which Cassirer transformed traditional transcendental philosophy into cultural philosophy. Instead of the purely rational cognition that has always held primacy in modern philosophy, there emerges a plurality of symbolic forms, each expressing a specific spontaneity of the human spirit. In the first volume of the Philosophy of Symbolic Forms, Cassirer examines language as a symbolic form, which he systematically grounds in a theory of cultural meaning comprehension. His effort to establish a methodological foundation for the humanities leads Cassirer to conclude that general epistemology, in its conventional form, is insufficient to clearly differentiate the various fundamental forms of understanding the world.