Remo Largo is a Swiss paediatrician, polymath, and child development expert, and this book is the remarkable product of more than forty years of research and medical experience. Largo's comprehensive view of humanity encompasses evolutionary biology, philosophy, pedagogy, psychology, medicine and sociology, as it traces our development as individual humans from the beginnings of evolution to the modern world. We travel from the evolution of genes, through the development of cognitive, linguistic and social abilities in humans, to questions of learning and the environment.In ten parts, Largo takes us towards a full understanding of his theory of human thriving, the 'Fit Principle,' which argues that humans strive to live in harmony with their environments. His theory rests on a holistic approach that sees the diversity of humans, the unique nature of each individual, and the interaction of individual and environment as the basis of human existence.