Henry Thomas Hamblin (1873-1958) was an English mystic, author, and editor, recognized as a significant proponent of applied spiritual philosophy in the early 20th century. He founded The Science of Thought Review and the Science of Thought Institute, teaching that aligning one's thoughts with universal spiritual laws leads to well-being, prosperity, and personal development. Despite early life challenges including limited education and personal tragedy, Hamblin established a successful optician's business before dedicating himself fully to his spiritual work. His philosophy emphasized the power of thought and personal responsibility for one's circumstances, advocating for disciplined mental practices and constructive action to achieve harmony and success. His writings, including the widely circulated 'Within You Is the Power,' influenced many and continue to be preserved through The Hamblin Trust.

Hamblin reported profound mystical experiences throughout his life, characterized by a sense of divine presence, peace, and love, which led him to seek answers beyond formal religious doctrines. He developed a philosophy centered on the immanence of divine law and the creative power of thought. This system, often termed 'Applied Right Thinking,' posited that the universe operates under immutable spiritual laws and that life's disruptions stem from deviations from this inherent harmony. Influenced by figures like Dr. Herbert A. Parkyn, Hamblin taught that thoughts are the primary architects of external reality, with the subconscious mind acting as a creative force shaped by mental habits. He believed that health, joy, and achievement are natural outcomes of living in accordance with what he called 'Cosmic Law.'

A core tenet of Hamblin's teaching was the individual's responsibility for their life circumstances, mediated through their mental attitudes and the law of cause and effect operating via thought. He stressed that by mastering thought, disciplining imagination, and cultivating character, individuals could positively influence their life's trajectory. However, Hamblin cautioned against relying solely on mental visualization, asserting that constructive thought must be coupled with constructive action. He maintained that lasting success is built upon a foundation of character, discipline, and perseverance, integrating spiritual principles with practical application in daily life.

Hamblin began his publishing career in the early 1920s, quickly becoming a leading voice in British New Thought with his book 'Within You Is the Power.' Throughout his career, he authored over forty books and booklets, many of which were translated and distributed internationally. He established and edited 'The Science of Thought Review,' a magazine dedicated to applied spiritual philosophy that later evolved through several title changes. In London, he founded the Science of Thought Institute, which served as a center for instruction and organization of his philosophical system, aiming to merge mystical insight with practical ethics and disciplined living.

Hamblin was also a significant contributor to Arthur F. Sheldon's 'The Business Philosopher' magazine, where he published a series titled 'The Fundamentals of True Success.' Drawing on his own business background, he presented success as the result of applying spiritual laws through disciplined thought, character, and consistent effort, rather than mere luck. He argued for the necessity of action alongside imagination and emphasized that character is truly tested after success is achieved. To preserve his work, The Hamblin Trust was established, continuing his legacy through reprints and online activities after the sale of his former residence. Hamblin's philosophy, integrating mysticism, mental discipline, and practical ethics, continues to be recognized for its emphasis on spiritual law as the basis for personal and professional conduct.

“What for lack of a better title is termed 'Science of Thought' is based on the ancient truth that an interior harmony and order exists, that it is ever present, and that it is the eternal, unchanging Reality. It follows that the disorders of life are due to a departure on man's part from this inherent harmony and order. Life is governed by certain laws which, if obeyed, bring forth health, wholeness, joy and sufficiency of all good. It is natural for life to be harmonious, orderly and beautiful. We do not have to create these states by huge effort; they are the natural order of things, which will manifest as soon as we cease to distort life, so to speak. We can distort a tennis ball by squeezing it, but as soon as we let it go it flies back to its original round shape, simply because that is its natural form. We do not have to make the ball round: all that we have to do is leave off distorting it”