George Leonard is one of the founders, along with RichardHeckler?, and WendyPalmer? of Milpatas Aikido, and one of the early generation of American Aikidoka. Leonard has studied human performance, and "Mastery" - the title of one of his books - for decades, in many guises. Like some of his contemporaries he has applied martial arts training techniques and training models in other domains, arguing persuasively that all practices are possible subjects of Mastery.
Leonard is an author (obviously) as are many of his contemporaries. He consults on the practices he teaches, as do many of his colleagues.
Books: