Norbert Wiener was one of the great mathematicians of this century. The Collected Worksreprint all of Wiener's scientific and scholarly papers, with commentaries by prominent scholars that place them in the context of present day research. The first three volumes cover Wiener's contributions spanning numerous branches of mathematics, mathematical philosophy, relativity, and quantum mechanics. This fourth and final volume contains his work in the field he christened "cybernetics" - a synthesis of communication and control in animal, man, and machine - and its applications in engineering, neurophysiology, and in particular encephalography and sensory prosthesis. Wiener's incisive social, education, and literary essays are also included. This volume is particularly timely in that many of today's publicly debated problems - the social and moral consequences of automation, the educational process, and the social responsibilities of scientists - were clearly foreseen by Wiener 40 years ago. The solutions he proposed then are illuminating now more than ever. Commentaries on the papers in Volume IV are written by W. R. Ashby, J. S. Barlow, D. Bohm, J. G. Burke, B. G. Farley, D. K. Ferry, J. Garcia Ramos, E. L. Gilbert, T. Kailath, H. Lev-Ari, R. Mann, O. K. Moore, P Masani, B. R. Myers, E. Nagel, P Pay, R. S. Phillips, B. Randell, A. Rosenblueth, R. S. Rudner, R. Saeks, A. L. Samuel, H. von Foerster, M. S. Watanabe, and R. L. Wilder. Some of these commentaries are comprehensive essays on topics that Wiener's work has put on the intellectual horizon. P Masani, University Professor of Mathematics at the University of Pittsburgh, and a former collaborator of Wiener, also edited the first three volumes of the Collected Works.