This book, based on the Tanner lectures on Human Values that Justice Stephen Breyer delivered at Harvard University in November 2004, defines the term "active liberty" as a sharing of the nation's sovereign authority with its citizens. Regarding the Constitution as a guide for the application of basic American principles to a living and changing society rather than as an arsenal of rigid legal means for binding and restricting it, Justice Breyer argues that the genius of the Constitution rests not in any static meaning it might have had in a world that is dead and gone, but in the adaptability of its great principles to cope with current problems.

Giving us examples of this approach in the areas of free speech, federalism, privacy, affirmative action, statutory interpretation, and administrative law, Justice Breyer states that courts should take greater account of the Constitution's democratic nature when they interpret constitutional and statutory texts. He also insists that the people, through participation in community life, can and must develop the experience necessary to govern their own affairs. His distinctive contribution to the federalism debate is his claim that deference to congressional power can actually promote democratic participation rather than thwart it. He argues convincingly that although Congress is not perfect, it has done a better job than either the executive or judicial branches at balancing the conflicting views of citizens across the nation, especially during times of national crisis. With a fine appreciation for complexity, Breyer reminds all Americans that Congress, rather than the courts, is the place to resolve policy disputes.

Active Liberty is a declaration of the first importance, made by a judge often regarded as one of the court's most brilliant members.