Teachers are instruments of learning, not simply conductors of a class.
Just as the conductor of an orchestra doesn’t actually produce the sound that creates music, teachers do not produce learning; they simply do their best to set the stage for it to occur.
Maria Montessori understood this deeply, placing a maniacal focus on the construction of the environment in Montessori schools. Here, teachers work to create and maintain a particular environment and help the students to spend as much time as possible learning.
My personal epiphany came when assigning students a writing task during my practicum. After walking around to help, I felt a pang of guilt. What do I do now? How can I help them more? The answer, I realized, was to let them focus and work. This learning wasn’t about me, but how the action and materials I’d prepared would help them learn.
That’s not to diminish the role of the teacher. Sometimes they should indeed take on a role more akin to an instrument, where a direct interface with the student is the best way to learn. Adults benefit from lectures! But sometimes this instrumental role is better delegated to an environmental resource, whether a book, tool, or even a type of action.
To be able to discern which orchestration will create the best results and to scientifically improve upon each attempt is the role of the teacher.