This volume collects 22 of Irving Kaplansky's research papers. Each is accompanied by an updating afterthought, often including references to later papers by other authors. In addition, there are eight hitherto unpublished papers, ranging over a variety of topics.

Irving Kaplansky is one of the top mathematicians of this continent of this century. He was the Director from the MSRI 1984-1992. He has made many contributions to many fields of mathematics and they are very valuable. In this volume, 22 of his research papers are collected. Each is accompanied by an updating afterthought, often including references to later papers by other authors. In addition there are eight hitherto unpublished papers. These range over a variety of topics and will be of interest to many readers.