Methods of Mind-Training, Concentrated Attention And Memory

I AM often asked why I was led to change the methods of teaching which I had pursued with more or less success for thirty years.
Rather should the question be why I had adopted a method at all after so many years of teaching without any; for, in common with many others of my profession, my teaching had lacked method.
In order that the motive for adopting a different course may be better understood, it is needful to consider some of the causes which had produced in my mind serious dissatisfaction with the customary school work and its results.