This book reflects the author's lifelong interest in the history of halakhah. What stimulated change, and why? What happened when strong forces impinged on halakhic observance and communities had to adapt to new circumstances? The book opens with a brief description of the dramatis personae who figure throughout the essays: Rashi and the Tosafists. Further chapters discuss halakhic commentaries and their authors; usury, moneylending, and pawnbroking; Gentile wine; and the self-image of the Ashkenazic community. Throughout, the book shows that the line between adaptation and deviance is a fine one, and that where a society draws that line is revelatory of its values and its self-perception. Many of the chapters presented here are already well known in the field; two are completely new. Most of those previously published have been updated, and the major chapter on pawnbroking has been significantly expanded.