A signal is comprehended if it serves to make us notice the object or situation it bespeaks. A symbol is understood when we conceive the idea it presents.

She was one of the first women to achieve an academic career in philosophy and the first to be popularly and professionally recognized as an American philosopher. Langer's first major work Philosophy in a New Key put forth an idea that has become commonplace today: that there is a basic and pervasive human need to symbolize to invent meanings and to invest meanings in one’s world.  435–438 
"A Logical Study of Verbs" Journal of Philosophy 24 1927 pp.

She was one of the first women to achieve an academic career in philosophy and the first to be popularly and professionally recognized as an American philosopher. Susanne Katherina Langer (née Knauth) (20 December 1895 – 17 July 1985) was an American philosopher of mind and of art who was influenced by Ernst Cassirer and Alfred North Whitehead. Langer is best known for her 1942 book Philosophy in a New Key.