In 1931, while he was a research instructor in chemistry at Brown University, Lars Onsager published two papers on the theory of reciprocal relations for irreversible processes, and thereby laid the foundations for the now flourishing subject of irreversible thermodynamics. As a most fitting recognition of the thirtieth anniversary of this achievement, Brown University played host, this past June, to an International Conference on Irreversible Thermodynamics and the Statistical Mechanics of Phase Transitions (sponsored by the International Union of Pure and Applied Physics, the National Science Foundation, and the Air Force Office of Scientific Research). The conference began with a suitably impressive ceremonial session at which President Barnaby Keney of Brown conferred the University's honorary degree of Doctor of Science upon Onsager, who is now J. Willard Gibbs Professor at Yale.