The judicial power ought to be distinct from both the legislative and executive, and independent upon both, that so it may be a check upon both, as both should be checks upon that.

John Adams articulated this principle during the revolutionary-era debates over how to design republican governments that would not collapse into tyranny. In Massachusetts politics especially, Adams argued for a constitutional structure that separated powers among legislative, executive, and judicial branches, each able to restrain the others. His thinking drew on English constitutional experience and Enlightenment political theory (notably Montesquieu), but he pressed the point with unusual force: courts must not be dependent on lawmakers or governors for their decisions. The idea became influential in American constitution-making in the 1770s and 1780s, shaping state constitutions and later informing the federal Constitution’s commitment to an independent judiciary.

The quote expresses a core separation-of-powers argument: justice cannot be impartial if judges are beholden to the political branches whose acts they may need to review. Adams frames judicial independence not as judicial supremacy, but as part of a balanced system of mutual restraints. The judiciary should be insulated enough to apply law without fear or favor, yet still situated within a constitutional architecture where each branch checks the others. The significance lies in its early American articulation of what later becomes a standard justification for life tenure, protected salaries, and institutional autonomy for courts—mechanisms meant to secure the rule of law against transient political pressures.