Wattles' best known work is a 1910 book called The Science of Getting Rich in which he explained how to become wealthy. He claimed to have personally "tested" the principles he described and they apparently worked, for although he had lived most of his life in poverty, in his later years he was a prosperous man.

In the preface to The Science of Getting Rich, perhaps one of the greatest books ever written, Wallace Wattles advises us to limit our study (as he must have himself) to "the monistic theory of the universe – the theory that One is All, and that All is One; that one Substance manifests itself as the seeming many elements of the material world.

Wattles was associated with the Chicago-based school of New Thought that centered around the teachings of Emma Curtis Hopkins. Through his personal study and experimentation he claimed to have discovered the truth of New Thought principles and put them into practice in his own life and wrote books outlining these principles.

This theory is of Hindu origin, and has been gradually winning its way into the thought of western world for three hundred years. It is the foundation of all the Oriental philosophies, and those of Descartes, Spinoza, Leibnitz, Schopenhauer, Hegel and Emerson."

He continues, "The reader who would dig to the philosophical foundations is advised to read Hegel and Emerson for himself."

Wallace Wattles wrote several books including:
* The Science of Getting Rich,
* The Science of Being Great,
* The Science of Being Well,
* Making of the Man Who Can,
* Health Through New Thought and Fasting,
* Several shorter manuscripts,
* plus a novel, Hellfire Harrison.

However, it is for his prosperity classic, The Science of Getting Rich that he is best known.

Through his tireless study and application of New Thought Principles Wallace was able to turn his life from poverty and failure in a prosperous way of living. Having discovered these secrets, Wallace began to write books to share these principles and Universal Laws with the world.

His daughter Florence has been quoted as saying, "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 died in 1911, not long after the 1910 publication of The Science of Getting Rich. His books, although know and used by the "lucky few" are finally being re-released to the public and are once again are assisting thousands of people to live a more complete life.

Rhonda Byrne author of the book "The Secret" has consistently credited "The Science of Getting Rich" by Wallace Wattles with inititating the search that would lead her to understanding of the secret.