This book provides the reader with a modern and comprehensive overview of nuclear polarization theory. The understanding of polarization phenomena greatly enriches data obtained from scattering and nuclear reactions by providing information on the interaction that can change spin orientation as well as important verification data for the study of nuclear structures and reaction mechanisms. The author methodically derives the polarization theory of nuclear reactions for various types of elastic scattering and two-body direct reactions between particles of different spin and unpolarized target...