Harlan Tarbell, in his introduction to The Tarbell Course in Magic writes:
Hubbard, himself, was a great teacher. Those at whose feet he sat, in turn sat at his feet. he taught the love of man for his work; that every man was born for SERVICE and the greatest man was he who served best. Like Arthur Frederick Sheldon he believed that MASTERSHIP is doing the right amount of the right things, in the right way at the right time, in the right place, the right number of times, and always in the right spirit.