Mental decrepitude and incapacity have troubled the United States Supreme Court from the 1790s to the 1990s. The history of the Court is replete with repeated instances of justices casting decisive votes or otherwise participating actively in the Court's work when their colleagues and/or families had serious doubts about their mental capacities. Contrary to conventional wisdom among legal scholars and historians, a thorough survey of Supreme Court historiography reveals that mental decrepitude has been an even more frequent problem on the twentieth-century Court than it was during the nineteenth. The historical evidence convincingly demonstrates that mental decrepitude among aging justices is a persistently recurring problem that merits serious attention.

More than seventy years ago, former Justice and future Chief Justice Charles Evans Hughes emphasized publicly that "[i]t is extraordinary how reluctant aged judges are to retire and to give up their accustomed work." Over the ensuing years little has changed. The United States Supreme Court since 1990 has featured four justices who continued serving after reaching the age of eighty: William J. Brennan, Jr., Thurgood Marshall, Harry A. Blackmun, and John Paul Stevens. Chief Justice Hughes was an early proponent of mandatory judicial retirement at age seventy-five, and he pointedly warned that "the importance in the Supreme Court of avoiding the risk of having judges who are unable properly to do their work and yet insist on remaining on the bench, is too great to permit chances to be taken." But no constitutional reform has occurred, and thus it remains undeniably true, as Chief Judge Richard A. Posner observed in 1995, that "[t]he judiciary is the nation's premier geriatric occupation." A careful review of both Supreme Court Justices' aggregate biographies, and the little-remembered efforts to enact a corrective amendment, shows that the Court's history offers some powerfully important present-day lessons and reveals how both scholarly knowledge and conventional wisdom are woefully incomplete. Today the conclusion unfortunately remains, just as Charles Evans Hughes said in 1928, that "[t]he exigency to be thought of is not illness but decrepitude."