This essay, published by the Center on the Legal Profession at Harvard Law School, presents a practical vision of the responsibilities of lawyers as both professionals and as citizens at the beginning of the 21st century. Specifically, it seeks to define and give content to four ethical responsibilities that the authors believe are of signal importance to lawyers in their fundamental roles as expert technicians, wise counselors, and effective leaders: responsibilities to their clients and stakeholders; responsibilities to the legal system; responsibilities to their institutions; and responsibilities to society at large. The fundamental point is that the ethical dimensions of lawyering for this era must be given equal attention to—and must be highlighted and integrated with—the significant economic, political, and cultural changes affecting major legal institutions and the people and institutions lawyers serve.