This book contains lectures presented at the MIT symposium on the 100th anniversary of Norbert Wiener's birth held in October 1994. The topics reflect Wiener's main interests while emphasizing current developments. In addition to lectures dealing directly with problems on which Wiener worked, such as potential theory, harmonic analysis, Wiener-Hopf theory, and Paley-Wiener theory, the book discusses the following topics: Fourier integral operators with complex phase (a contemporary successor to the Paley-Wiener theory); statistical aspects of quantum mechanics and of liquid crystals; financial markets, including the new trading strategies for options based on Wiener processes; statistical methods of genetic research; and, models of the nervous system, pattern recognition, and the nature of intelligence.The volume includes reviews on Norbert Wiener's contributions from historical and current perspectives. This book gives mathematical researchers an overview of new mathematical problems presented by other areas and gives researchers in other fields a broad overview of the ways in which advanced mathematics might be useful to them.