The concept of education through recreation was first applied in the 19th century to childhood develop ment. George H. Read, the Chicago sociologist who identified the developmental role of play in childhood, divided human activity into 3 general types: work, art and play. The principle was broadened to include young adults, but the emphasis was restricted to phys - ical activities. It was the basis for the rise of organized sports and initiatives such as the Olympic Games. Another Chicago sociologist, Nels Anderson, who spent a considerable part of his career at the University of New Brunswick, developed the concept that the currency of life is time: time spent working earns time for leisure. In his book explaining this concept, Anderson referred to the English educationist Lawrence P. Jacks, who had been asked by the United States National Recreation Association to consider the matter for a booklet endorsing outdoor activities in the National Parks. Jacks’ wonderful summary has been appropriated by various authors and followers of Zen Buddhism since it was written in 1932: "A master in the art of living draws no sharp distinction between his work and his play, his labour and his leisure, his mind and his body, his education and his recreation. He hardly knows which is which. He simply pursues his vision of excellence through whatever he is doing and leaves others to determine whether he is working or playing. To himself he always seems to be doing both. Enough for him that he does it well."