One of the key processes in developmental learning is emulating the words and actions of others.  This imitation (the sincerest form of flattery), challenge our imaginations to what we each perceive as perfection.  As an example, Thomas Edison was not a great inventor himself, but a great innovator of combining other people's inventions. 
Reading other writers' works stimulates our minds in the very same way.  Innovative ideas are not only enhanced, but re-created as greater extensions.  Vocabulary is also increased, style improved, and the descriptive flow of tale made flawless.  Reading is probably the greatest tool for every writer looking to improve their craft and ability.