This volume is a collection of lectures and selected papers by Giorgio Parisi on the subjects of field theory (perturbative expansions, nonperturbative phenomena and phase transitions), disordered systems (mainly spin glasses) and computer simulations (lattice gauge theories).

Part 1 Field theory: field theoretical approach to second-order phase transitions in two- and three-dimensional systems; an introduction to scaling violations; on non renormalizable interactions; the physical basis of the asymptotic estimates in perturbation theory; the Borel transform and the renormalization group; singularities of the Borel transform in Gauge theories; on infrared divergences; critical exponents and large-order behaviour of perturbation theory; quartic oscillator. Part 2 Disordered systems: an introduction to the statistical mechanics of amorphous systems; supersymmetric field theory and stochastic differential equations; spin glasses and optimization problems without replicas; spin glass theory; on the emergences of tree-like structures in complex systems; on the multifractal nature of fully developed turbulence and chaotic systems. Part 3 Simulations: recent progresses in gauge theories; the strategy for computing the hadronic mass spectrum; prolegomena to any future computer evaluation of the QCD mass spectrum; a short introduction to numerical simulations of lattice gauge theories; the APE computer and first physics results; principles of numerical simulations.

"... a selection of twenty-three of his papers, an impressive illustration ... his work on spin glasses and disordered systems has been awarded the 1992 Boltzman medal in statistical mechanics. This selection of Parisi's work ... touches upon many aspects of modern theoretical physics." "This book is a wonderful illustration of the unity and of the power of theoretical concepts in the hands of an amazingly imaginative physicist with universal interests. Very often one hears complaints about the hyperspecialization of modern science; indeed to make progress on a definite topic requires a good specialized background, but it does not prevent scientists with such a wide angle inquisitive mind to understand and contribute significantly to so many different areas. Fermi, Feynman, Landau were like that in their time; similarly Parisi has been illustrating over the last twenty years how much field theory, scaling, universality, complex systems, disordered systems ..., were powerful ways of looking at science. This collection of reprints contains a good illustration of this theme, with some articles which are not readily available in standard journals, and it is thus a pleasure to welcome this new book." Edouard Brezin ENS (France), 1992 "Parisi is the modern standard-bearer of a distinguished school of universal theorists which can be traced back to Fermi and Landau. This is not only due to the importance and originality of his scientific contributions but also for his efforts to disseminate what is known at the frontiers of knowledge to a larger audience of young physicists." "The breadth of coverage imparts a deep understanding of stochastic phenomena, field theory and disordered systems and their interrelations." "... a must for anyone seriously interested in field theory or the theory of disordered systems." Nicolas Sourlas Physics World, 1993 "Parisi, whose work spans a wide range of theoretical physics, was awarded the Boltzmann Medal in 1992 and his selection of lectures and papers will form a valuable reference for theorists working in these areas." Contemporary Physics, 1993 "This book contains some of the best lectures of Giorgio Parisi, given over the last 20 years at several schools and conferences (mainly Cargese and Les Houches), together with some research papers that are meant to complement them. The works have been selected by Parisi, who completes the book with an original introduction in which he gives reasons for the choices ... a very useful collection of material by one of the most outstanding physicists of his generation. The reader will enjoy the book and learn many things, even if already acquainted with the work of the author." Emili Elizalde Mathematical Reviews