A major constitutional issue in the twentieth century is the extent to which the U.S. Constitution should be interpreted to fit changing times and circumstances. In the latter part of the nineteenth century, the Supreme Court dispensed a "mechanical jurisprudence" based on an "objective" interpretation of the Constitution and the "original intent" of its authors. In the twentieth century, the Court has tended to respond to changing social conditions with flexible and expansive interpretations of basic constitutional principles. The "popular will" became a factor in decisions which has troubled "legal purists" who believe that the courts should be above public opinion as judges apply legal logic and precedents to reach their conclusions. The "purists" believe the task is not to keep the Constitution in tune with the times, but rather to keep the times in tune with the Constitution. In contrast, "pragmatic instrumentalists" believe that the Constitution must be interpreted to meet contemporary social concerns and problems, especially injustices suffered by minority groups. This view was articulated by two twentieth century Chief Justices of the Supreme Court: Harlan Fiske Stone (in the 1930's) and Earl Warren (in the 1950's and 1960's). During the 1970's and 1980's, there has been considerable tension between the "pragmatic instrumentalists" and the "legal purists." (JP)