Description: William Thurstons work has had a profound influence on mathematics. He con nected whole mathematical subjects in entirely new ways and changed the way mathematicians think about geometry, topology, foliations, group theory, dynamical systems, and the way these areas interact. His emphasis on understanding and imagination in mathematical learning and thinking are integral elements of his distinctive legacy. This four-part collection brings together in one place Thurstons major writings, many of which are appearing in publication for the first time. Volumes IIII contain commentaries by the Editors. Volume IV includes a preface by Steven P. Kerckhoff. Volume I contains William Thurstons papers on foliations, mapping classes groups, and differ ential geometry. I Foliations, Surfaces and Differential Geometry Benson Farb David Gabai Steven P. Kerckhoff Editors COLLECTED WORKS OF WILLIAM P. THURSTON WITH COMMENTARY 201 Charles St., Providence, RI 02904