[2] Many of Larson's books remain in print today, more than 100 years after they were first published, and his writings influenced notable New Thought authors and leaders, including Religious Science founder Ernest Holmes.
In his early twenties he became interested in the Mental Science teachings of Helen Wilmans, Henry Wood, Charles Brodie Patterson et al.
In September 1901 he began to publish Eternal Progress, for several years one of the leading New Thought periodicals, building it to a circulation of over a quarter of a million.
He was a colleague of such notables as William Walker Atkinson, Charles Brodie Patterson, and Home of Truth founder Annie Rix Militz.
In 1918, Larson joined the staff of Science of Mind Magazine as an associate editor and frequent contributor.