This volume contains the collected works of the eminent chemist and physicist Lars Onsager, one of the most influential scientists of the 20th Century. The volume includes Onsager's previously unpublished PhD thesis, a biography by H C Longuet-Higgins and M E Fisher, an autobiographical commentary, selected photographs, and a list of Onsager discussion remarks in print. Onsager's scientific achievements were characterized by deep insights into the natural sciences. His two best-known accomplishments are his reciprocal relations for irreversible processes, for which he received the 1968 Nobel...