Arthur M. Young wrote two little read albeit influential and (to me) essential books, both published in 1976: The Geometry of Meaning and The Reflexive Universe. Along with the alchemical writings of C.G.Jung, they are the most important contemporary books about quaternity and ‘anthropo’ process. Young/Jung’s research inform SQ1’s model of exploratory learning; this is implicit in my use of quaternistic matrices and integral oppositions in tool designs. The Arthur Young web site provides much to investigate. The essays there are all excellent; for starters: “The Four Levels of Process“.