"As a Man Thinketh" is a literary essay by James Allen, published in 1903. It was described by Allen as "... dealing with the power of thought, and particularly with the use and application of thought to happy and beautiful issues. Allen has tried to make the book simple, so that all can easily grasp and follow its teaching, and put into practice the methods which it advises. It shows how, in his own thoughtóworld, each man holds the key to every condition, good or bad, that enters into his life, and that, by working patiently and intelligently upon his thoughts, he may remake his life, and transform his circumstances. It was also described by Allen as "A book that will help you to help yourself", "A pocket companion for thoughtful people", and "A book on the power and right application of thought.
The aphorism, "As a man thinketh in his heart so is he," not only embraces the whole of a man's being, but is so comprehensive as to reach out to every condition and circumstance of his life. A man is literally what he thinks, his character being the complete sum of all his thoughts.
As the plant springs from, and could not be without, the seed, so every act of a man springs from the hidden seeds of thought, and could not have appeared without them. This applies equally to those acts called "spontaneous" and "unpremeditated" as to those which are deliberately executed.
Act is the blossom of thought, and joy and suffering are its fruits; thus does a man garner in the sweet and bitter fruitage of his own husbandry.