In this book Benner speaking first person God, as in his book 'The Impersonal Life' ask some cutting to the quick questions of teachers.  They are very probing questions and any teacher would want to ask them of themselves, and then notice if the questions itself, brings out any hidden feeling of emotion (that you thought you had taken care of) still brooding and exerting its influence on the work you are doing.  This is a very good book for anyone, but if you consider yourself a teacher, then it will give you great insight.