'Self-actualization' refers to a core concept in both Carl Rogers' person-centred approach to psychotherapy and modern systems theory. Self-actualization stresses the links between humanistic approaches, systems (family therapy), 'old' holistic and dynamical thinking in psychology (in particular gestalt theory) and 'modern' systems thinking in the natural sciences. Most people believe in the essential difference between an engine and a human being, but still use cognitive tools from mechanical science. The intent of this book is to provide the reader with thoughts, ideas, metaphors and knowledge which are more adequate to understand the processes of life and our soul.