Hans Vermaak studied environmental sciences and organisational psychology in Utrecht and Florida. He received his science degree from the University of Utrecht in 1985. He worked as a faculty member at both the science and psychology departments of the University of Utrecht between 1982 and 1987. He was a social activist for many years and worked between 1987 and 1992 with the Institute of Environmental and Systems Analysis where he mediated conflicts between industry, government and the environmental movement and helped industries to create strategic environmental management. He followed courses in psychotherapy and counselling and has taught counselling since 1987 and has worked as an independent psychotherapist. He received a masters degree in Management Consulting from the ''Vrije Universiteit'' in Amsterdam in 1994 and works as a management consultant with the Twynstra Group since 1993. His principle area of consulting concerns change management in professional firms and institutions. He trains and coaches change agents and he heads the knowledge center ''Change Management'' of the Twynstra Group. He is a guest lecturer at several universities and frequently publishes articles and books on change management, professional organizations, coaching, futuring, etctera. His English publications include the articles "Conspiring fruitfully with professionals: new management roles for professional organisations", the paper "Prevailing Perspectives on Change" and the booklet "In Search of Corporate Learning; The Archipelago of Learning".