Charles Godfrey Leland was a humorist and folklorist. Leland worked in journalism, traveled extensively, and became interested in folklore and folk linguistics. He studied American and European languages and folk traditions. The Mystic Will: A Method of Developing and Strengthening the Faculties of the Mind, through the Awakened Will, by a Simple, Scientific Process Possible to Any Person of Ordinary Intelligence begins, "Firstly, that all mental or cerebral faculties can by direct scientific treatment be influenced to what would have once been regarded as miraculous action, and which is even yet very little known or considered. Secondly, in development of this theory, and as confirmed by much practical and personal experience, that the Will can by very easy processes of training, or by aid of Auto-Suggestion, be strengthened to any extent, and states of mind soon induced, which can be made by practice habitual. Thus, as a man can by means of opium produce sleep, so can he by a very simple experiment a few times repeated--an experiment which I clearly describe and which has been tested and verified beyond all denial--cause himself to remain during the following day in a perfectly calm or cheerful state of mind; and this condition may, by means of repetition and practice, be raised or varied to other states or conditions of a far more active or intelligent description."