What is the importance of education in Pygmalion by George Bernard Shaw?

There is no doubt that education is a central theme in George Bernard Shaw's Pygmalion. In the beginning of the play, Eliza Dolittle is introduced as an ignorant and illiterate child.  She speaks a type of Cockney that is considered low-class and uneducated.  She is also characterized as rude, sassy, and having no manners!

While she is selling flowers in Covent Garden, Eliza has a chance encounter with Colonel Pickering, who has come to London to study Phonetics (the sounds of human speech)  with Professor Higgins. Eliza then decides to seek out Professor Higgins to take lessons in Phonetics in order to improve her speech. She wants to learn how to speak correctly so that one day she can achieve her dream of becoming a sales girl in a flower shop.

This is where the importance of education comes in: not only does Eliza eventually learn how to speak properly, she also begins to seek out the deeper meaning of life.  As Dr. D. Prasad says in the The Criterion, 

Education is enlightenment...in Pygmalion, education is used as a tool for [freeing] working class individuals.

In other words, not only does education teach Eliza how to speak, it also allows her to leave her lower class life and make social progress! Additionally, Eliza gains spiritual enlightenment through education.  

She rises from ignorance and darkness to spiritual light (Prasad). 

So, education is important in Pygmalion because Eliza Dolittle learns how to speak correctly, which helps her attain social mobility that she would not have had before.  Additionally, education gives Eliza a new spiritual understanding of herself and the world around her.