His most famous work is a book called The Science of Getting Rich in which he explains how to get rich.
He personally "tested" the principles he describes in his book and they worked, as although he had lived most of his life in poverty, in his later years became rich.
Other books by Wallace include Health Through New Thought and Fasting, The Science of Being Great, The Science of Being Well, Making of the Man Who Can and a novel, Hellfire Harrison.
Little is known about Wattles' life.
He was born in the USA shortly before the civil war, and experienced much failure in his earlier years. Later in life he took to studying the various religious beliefs and philosophies of the world including those of Descartes, Spinoza, Gottfried Leibniz, Schopenhauer, Hegel, Swedenborg, Ralph Waldo Emerson, and others.
It was through his tireless study and experimentation that he discovered the truth of New Thought principles and put them into practice in his own life. He began to write books outlining these principles.
He practiced the technique of creative visualisation and as his daughter Florence relates, "He wrote almost constantly.
It was then that he formed his mental picture.
He saw himself as a successful writer, a personality of power, an advancing man, and he began to work toward the realization of this vision. He lived every page ... His life was truly the powerful life."
Wattles has been the author of numerous works as a part of the New Thought movement of the early 20th century.
Health Through New Thought and Fasting by Wallace D. Wattles, Elizabeth Towne
This contribution by Wattles discusses beliefs in the movement about healthy living through both mental and physical means.