Medicine and Natural Sciences: Collective Properties of Physical Systems is a collection of papers presented at the 24th Nobel Symposium on Collective Properties of Physical Systems, held in Aspenäsgärden, Lerum, Sweden on June 12-16, 1973. This book is organized into eight parts encompassing 35 chapters, and begins with overview of the fundamentals of renormalization group approach, phase transitions, and critical phenomena. These topics are followed by discussions on the solutions of the Kondo problem, the specific features of superfluid 3He, and the models to investigate the effects of limited dimensionality in solid systems. The subsequent parts cover the various aspects and principles of surface physics and high-energy excitations in solids. These parts also examine selective theories that provide significant insights in understanding the superstructure, ordering, and crystallography of physical systems. The last parts describe the electronic correlation functions and other properties of liquid crystals and liquids. Physicists, scientists, and research workers in the fields of medicine and natural sciences will find this book of great value.