Although the criticism for education never ceased, saying that education restrains the way we think and takes away our imagination, I still firmly believe that the main purpose of education is and should always be to set free our minds and spirits. Unrestrained spirits can play a considerably important role in both each individuals and the society as a whole. It's terrifying to imagine what a person would be like without a free mind -- always acting according to what others say or do, forever obeying rules and conventions, never questioning, never creating, he would be more like a machine rather than an independent man. Indeed, it would be much easier for a government to dominate such obedient citizens -- it would receive nothing but support and no longer need to be worried about protests or revolutions. However, for a nation crowded with restrained minds and spirits, the only thing waiting ahead is disaster. Without creativity and innovation, development would cease.The nation would remain unchanged until it be destroyed by others or collapse itself. The Qing Dynasty of Chinese history is a good example -- the whole nation was ruined by its rigid governors and citizens. The free of mind, on the other hand, will bring prosperity. Great developments such as the Renaissance and the two Industrial Revolutions were all brought about by creative spirits.
No one, however, is born with free minds and spirits. Instead, we get them in the process of learning and mostly from education. We never hear someone say that a three-year-old child has a free mind, although the mind of a child at that age is certainly not restrained. That is because the free of spirits and minds means questioning existing conventions and coming up with new ideas. That process must be based on certain knowledge. No matter how innovative we are, we can never create something from nothing, instead we are "standing on the shoulders of giants" and building our own palace by questioning and improving. Great innovators, no matter what industries they are in, are mostly well educated in their own fields -- Da Vinci had learned drawing from Verrocchio，Newton was graduated from Cambridge, and most quantum physicists in the 20th century has studied in Copenhagen University. Education can teach us knowledge and methods left by ancestors,therefore arouse our innovation and free our minds.
I concede that nowadays formal education in some part of the world is not open enough -- getting good grades in exams become the main purpose at school, and students' minds are restrained. This situation, however, is improving, especially in developed countries. In the United States, more and more schools have introduced discussion, experiments and social activities as part of the formal education. Students are encouraged to question anything taught by teachers and are allowed to try their own ideas in laboratories. In this way, students' spirits are freed, and they are getting more and more creative through education. As for developing countries such as India and China, though education resources are limited, educators are still trying their best to introduce more discussions in classes and more choices for students. 
Free minds and spirits are important, for they are main sources of innovation and fundamental forces for development. More and more educators have realized the importance of freeing youngsters' minds. It is and should always be the main purpose of education.