Does withholding knowledge stimulate or stunt learning?

Does refusing to share knowledge truly stimulate learning? I love to learn new things, and am constantly on some mission of discovery.  Over the years, I have tried to share my enthusiasm for learning with my students, and anyone else who will allow me to indulge my love of learning.  I have just as eagerly shared what I have learned as I have shared my enthusiasm for learning.  One of my greatest thrills as a teacher is to see curiosity light up the eyes of a student, and watch them begin their own journey of discovery. I don’t believe we are ever too old to learn new things.  I do believe that as soon as we choose to give up the quest for knowledge and understanding we limit our relevance to society.

Earlier today, I interacted with an intelligent, interesting individual who often writes some thought-provoking articles.  A recent article of his stimulated some study on my part and raised some questions, so I addressed those questions to the author, in the hope that he would help me understand his thought process better.  He responded in a rather unexpected way.  He indicated that he did indeed have the answers to my questions, but felt that sharing what he knew would discourage me from thinking independently and stunt my ability to aquire or generate knowledge.  If he answered my questions, that would somehow make him guilty of spoon-feeding me. 

How often has an intelligent, educated, and seemingly-wise teacher with a vast and valuable knowledge- and understanding-base quenched the desire that a student may have to learn simply by not embracing a desire to share?  How often is the learning process retarded, because those who have the knowledge will not share it with those who do not have it?  I have, at times, experienced this “what is mine is mine, and I will not share” attitude in the highly competitive research environment where it is believed by some that withholding knowledge grants power, and sharing knowledge weakens your position to dominate as a researcher.  How often does this attitude seep down into the classroom environment where the goal should be to encourage everyone to learn as much as they can?

Are there teachers who withhold answers just to ensure that the students do not grow to know more than they do?  Is this restricted sharing environment comforting for the teacher, and effective in stimulating the students to seek their knowledge elsewhere?  Are there teachers who are not motivated to take up the torch of lifelong learning?  Do our formal learning environments still accommodate teachers who have no interest in growing and developing, so they always have something new to share with their students?