What is the relationship of teaching and leadership? Is a great teacher a great leader? Is a great leader a great teacher?
To me it is the equivalent of the square and rectangle comparison. A rectangle doesn't have to be a square but a square has to be a rectangle. Likewise, a good teacher doesn't always have to be a good leader, but a good leader always has to be a good teacher. Please note however, not every teacher is a leader and not every leader is a teacher. Only good leaders are teachers, and not every good leader is a good teacher. Great leaders are good or even great teachers.
Teaching is serving, and any teacher who is concerned about their own agenda or self-promotion will come crashing down sooner or later (more likely sooner than later). For anyone who is self-serving, teaching is incredibly hard. Think about it. As a teacher, you may have anywhere between 20-35 students in front of you, all of whom want your attention in some fashion. And students have a keen sense of knowing when a teacher cares. The age old saying, "No one cares how much you know until they know how much you care," applies here. At some point, what is best for the student will come against your opinion, belief, wants, interests, etc. At some point, it will cost the teacher something and most likely something valuable. Then, what the teacher does determines whether he/she is a great teacher. Same applies to the leader. Every leader has a number of people before them (if they didn't then they aren't a leader, huh?), and each want the full attention of their leader for whatever reasons. Only a serving leader will allow himself/herself to give his/her full attention to those individuals.
The corporate environment or culture depends heavily on its leader. If the leader is an avid learner and teacher, then the organization will become a learning organization. Great leaders foster learning, exemplify learning, and value learning. First the leader must value learning. This value can have many different expressions from learning for learning sake to learning for practical reasons. Regardless a leader who stops learning stops leading. Second, a leader exemplifies learning. They don't merely talk about all their learning as though they have arrived. Instead they continue to learn, continue to read, continue to study, and continue to improve. I heard someone once say, "You can't grow without reading." While this is not entirely true, because there are many ways to grow and learn, it becomes true after a certain point in life. Third, a great leader fosters learning. They do this through communication, delegation, empowering others, etc. forcing the person(s) to learn to do a specific task, to research other options, etc. The great leader must be a communicator who must be willing to teach others various insights and skills.