Not everything that is learned is contained in books
To my opinion, books and real experience are two completely different sources of knowledge. It is really difficult to determine which of the two to be of much greater importance, because normally knowledge gained from experience complements that acquired from books, but not substitutes it. Comparing the features of the two sources, I would stress the following points of differences.
First, the knowledge gained from books is, to a certain extent, of abstract nature. Books are normally the collections of facts and general rules. Books give us the most complete overview of a subject in a more or less structured manner, covering all known details and exceptions. In some way, books are concentrations of knowledge and experiences of many generations of people, given in a concise and comprehensive way. Obtaining such knowledge just from the personal experience would take an immense amount of time or even would not be possible at all. The practical experience, gives us not general knowledge, but particular skills. Without these particular skills, all the knowledge gained from books might be just a useless collection of facts and rules. The best example of the importance of practical experience that comes to my mind is learning a foreign language. One can learn a lot of vocabulary and grammar rules, memorize many exceptions, but without actual applying of all this knowledge in real life conversations, writing letters and listening to real speeches, one can hardly be proficient in the language. The importance of having practical skills is also proved by the fact that most employers appreciate working experience above all grades and diplomas.
Another point of contrast between books and experience is that for some subject, such as economy of sociology, a book may represent a point of view of its author or authors. The conclusions given in the book might be out of date, or might be biased by the personal attitude of the authors. In this case, practical experience helps to build up personal perspective on the matter, to bring the matter up to date.
On the psychological grounds, learning from experience is much more efficient than reading books. Reading books is in most cases a passive action, which can be done without much effort. Despite the fact that there are people who can memorize thousands of papers, for a normal person, such work does not result in a deep, comprehensive knowledge base. On the contrary, doing things in practice, people have to overcome various difficulties, get through unknown areas, and pay attention to small details. The reward for these efforts is much more comprehensive and profound knowledge.
Summarizing the said above I want to admit that both books and practice is important in the process of learning. While none of the two can be considered as absolute substitute for the other, I would place the practical experience in a little bit advance position in terms of importance.
