This quotation, or a similar one, could as easily have been taken from the writings of Kurt Lewin, the seminal
thinker in the field of group dynamics. This is not surprising, considering that both of these men derived their
models of personal and social change from two sources: the work of the German psychologists, Koffka,
Kîhler and Wertheimer (whose experimental studies in perception and learning became the foundation of
Gestalt Psychology); and the contribution of a German researcher and physician, Kurt Goldstein) who
extended the principles to the study of the whole person. While each of these men, Lewin and Perls, were
dedicated to changing behaviour, they developed their ideas into what may appear to be very different and
seemingly polarised fields of application; individuals and systems. Lewin was a social psychologist, and
although he did not lose sight of the individual, what became "figural" for him was the social environment.
The major goal for him was social change. His work as a scholar and research scientist provided the
theoretical foundations of the field of applied behavioural science, which includes what is now known as
group dynamics, organisational development and large systems change.