The collection of articles in this volume represents the proceedings of the inau- gural Conference of the Institute of Theoretical Matter Physics at the University of Florence, Italy, June 7-13, 1990. The aim of this Institute (sponsored by the Con- sorzio Interuniversitario di Fisica della Materia, INFM) is to foster interdisciplinary approaches to theoretical problems in Solid State, Electronics and Optics. Corre- spondingly, the Conference surveyed a broad scope of modern analytic techniques in nonlinear science and their application to novel liquids, solids and optical environ- ments. The Conference was held at Centro Studi CISL, a magnificent Villa up to Florence. The major topics addressed through survey and specialized lectures, discussions and posters were: Complexity and Coherence in spin glasses, associative distribu- tive memory, low dimensional electronic materials, magnets, Josephson junction ar- rays, optics, semiconductors, convection cells, material science, high-temperature superconductivity; Physics of Quantum Devices such as nonlinear feedback oscilla- tors, macroscopic quantum tunneling, hetero structures, quantum ballistic devices, tunneling in atomic devices; Field Theory and Statistical Mechanics, especially for soliton-bearing and quantum chaotic systems. Many exciting ideas and results were presented and debated in lively fashion. Perhaps two major themes were evident throughout the workshop.