The system of healing described in Science and Health with Key to the Scriptures earned Mary Baker Eddy a number of theological critics—but it also earned her the respect of those trying to establish a healing ministry themselves. One of them was Lyman P. Powell, an Episcopalian minister and well-known speaker during the early years of the 20th century, who had a deep respect for Christian Science. He stated, "It is turning the thoughts of men back to the power the mind spiritualized has over the body." He wrote this extensive biography of Mary Baker Eddy, whom he considered to be America's greatest woman.